• Korean Journal of Health Education and Promotion
• /
• v.33 no.2
• /
• pp.39-45
• /
• 2016

Objectives: The purpose of this study is to parenting attitudes perceived by adolescents into different groups and to examine the impact of sub-factors of parenting attitudes on smart phone addiction. Methods: Data was collected by distributing questionnaires to high school students located in the nationwide regions and a total of 1,020 people were surveyed. Inconsistent parenting attitudes were divided into the consistent group and inconsistent group to carry out descriptive statistics, multiple regression, and path analysis. Results: In both the consistent and inconsistent parenting attitude groups, it was found that among the sub-factors, interest(p<.01) had the biggest impact on smart phone addiction. Inconsistent parenting attitude group was found that smart phone addiction levels in adolescents were more higher than consistent parenting attitude group. Conclusions: Through the above results, it was confirmed that smart phone addiction to directly impact parenting attitude. This implies that when raising their children, parents should display consistent attitudes in order to prevent addictive smart phone usage among adolescent.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1418-1420
• /
• 2008

In this paper, the light emitting efficiency, spectrum, and the lifetime of the phosphorescent devices, whose emission characteristics are strongly dominated not only by the energy transfer but also by the charge carrier trapping induced by the emissive dopant, are explained by differences in the energy levels of the host, dopant, and nearby transport layers. On the basis of our finding on device performance and photocurrent measurement data by time-of-flight (TOF), we investigated the effect of the difference of carrier trapping dopant and properties of the host materials on the efficiency roll-off of phosphorescent organic light emitting diode (OLED), along with a physical interpretation and practical design scheme, such as a multiple host system, for improving the efficiency and lifetime of devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1638-1641
• /
• 2008

We have investigated the effectiveness of a gravure printing method for the fabrication of organic light-emitting diode (OLED) and Organic Thin Film Transistor (OTFT). Printing of the organic layers was performed with a small-scale gravure coating machine, while the metallic layers were vacuum-evaporated. Devices with gravure-printed layers are at least comparable with the spin-coated devices. Effects of the solvent formulation and surface energy mismatch between the organic layer materials on the printed patterns and device performance were discussed. We will present the initial design and experimental data of OTFT fabricated by roll-type soft contact transfer process.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.553-556
• /
• 2008

We hereby report novel driving scheme to eliminate effect of "residual" image sticking (RRI) problem which arises due to hysteresis problem in Thin Film Transistor (TFT) in AMOLED Displays. The driving scheme applies "black" voltage after every data voltage period in order to drive AMOLED in uni-direction. The system can be easily implemented with 120 Hz driving scheme which is well matured in AMLCD industries. Our analyses show systematic evaluation of the problem and thereby solving it by simple methods which will be significantly effective of driving OLED towards mass manufacturing stage.

• Korean Journal of Child Studies
• /
• v.13 no.2
• /
• pp.175-188
• /
• 1992

This study investigated the relation between stressful life events and adjustment in elementary school children, with particular emphasis on the potential main and stress-buffering effects of social support and social problem solving skills. 4-6 graders (N=170) completed the Social Support Appraisals Scale(SSAS) and social problem solving skills task. The SSAS is a 31-item measure that taps the child's perceptions or appraisals of family, peer, and teacher support. Their parents provided ratings of stress in the child's environment and ratings of the child's behavioral adjustment. Teachers provided ratings of the child's behavioral and academic adjustment. Hierarchical multiple regression analyses and graphic display were used to analyze the data. The major findings were that (1) The results for parent-rated problems supported a stress-buffering model for family support and problem solving. (2) The results for teacher-rated problems were consistent with the stress-buffering model of social support. (3) The results for grade-point average supported a main effect model for problem solving. peer support, and family support. In addition, teacher support had the strongest stress-buffering effect on grade-point average.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1640-1644
• /
• 2006

The first issue that should be overcome in copper process is its poor adhesive strength between pure copper film and glass substrate. In this study, defining the adhesive strength of pure copper film on various substrates and clarifying the key deposition parameters are presented for the investigation of copper process. First, using different kinds of surface plasma treatments were studied and the results showed that the adhesive strength was not improved even though the roughness of glass substrate surface was increased. Second, adding an adhesive layer between glass substrate and pure copper film was used to enhance the adhesion. Based on the data in the present paper, adopting copper alloy film as an adhesive layer can have capability preventing peeling problem in copper process. Besides, Cu/Cu alloy structure could be etched with the same etchant with better taper angle than the one with single layer of Cu. Unlike Cu/Mo structure, there is no residual problem for Cu/Cu alloy structure during etching process. Finally, this structure was examined in electrical test without significant difference in comparison with the conventional metal process.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1025-1028
• /
• 2005

Microcrystalline Si (${\mu}c-Si$) TFTs were fabricated using a conventional bottom gate amorphous Si (a-Si) process. A unique ${\mu}c-Si$ deposition technique and TFT architecture was proposed to enhance the reliability of the TFTs. This three-mask TFT fabrication process is comparable with existing a-Si TFT procesess. In order to suppress nucleation at the bottom interface of Si, before deposition of the ${\mu}c-Si$ an $N_2$ plasma passivation was conducted. A typical transfer characteristic of the TFTs shows a low off-current with a value of less than 1 pA and a sub threshold slop of 0.7 V/dec. The DC stress was applied to verify the use of ${\mu}c-Si$ TFTs for AMOLED displays. After 10,000 s of application of the stress, the off-current was even lowered and sub-threshold slope variation was less than 5%. For AMOLED displays, OLED pixel simulation was performed. A pixel current of 13 ${\mu}A$ was achieved with $V_{data}$ of 10 V. After the simulation, a linear equation for the pixel current was suggested.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1361-1363
• /
• 2005

In this paper, we report on the performance stability of solution processible OTFT devices with Au/Ti and ITO source-drain (S/D) electrodes. It appears that the contact resistance of the S/D electrode strongly affects the stability of OTFT devices. Interestingly, the devices with the Au/Ti electrode showed lower mobility than those with the ITO (S/D) devices. The field effect mobilities of the devices with the Au/Ti and ITO electrodes were 0.06, and $0.44cm^2/Vs$, respectively. However, the mobility of the device with the Au/Ti electrode was increased up to $0.26cm^2/Vs$ after 2 weeks, while the mobility of the device with ITO electrode was slightly decreased down to $0.41cm^2/Vs$. The experimental data show us that ITO could be used as the S/D electrode for low-cost OTFT devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.241-244
• /
• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Successful integration of gate circuit, transmission gate and level shifter was performed in a large area uniformly. Uniformity and high performance from high quality grains of SLS technology make it possible to come true a uniform large size LTPS TFT-LCD with half number of data driver IC's used in typical a-Si LCD. High aperture ratio of 65% was obtained using an organic inter insulating method, which lead a high brightness of 500cd/cm2.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.21-24
• /
• 2003

The understanding of the mechanism of device degradation has been accomplished recently, for devices using $AlQ_3$ electron transport and emitter molecule. In this presentation the experimental evidence for the degradation mechanism of $AlQ_3$ based devices will be reviewed, showing that the hypothesis of an unstable $AlQ_3^+$ cation explains a large amount of experimental data. This hypothesis, however, explains not only the room temperature device degradation in time but also sheds light on temperature stability of OLEDs. Dependence of half-life of a series of devices with an emitter layer composed of a mixture of $AlQ_3$ and different hole transport molecules (mixed emitter layer) will be discussed when they are operated at elevated temperatures. These results can also be explained in the framework of an unstable $AlQ_3^+$ species. An OLED structure containing a doped mixed emitter layer will be described, which shows extraordinary stability, half-life of 1200 hours at operating temperature of 70 C and initial luminance of 1650 $cd/m^2$. We will also discuss a novel Black $Cathode^{TM}$ OLED with reduced optical reflectivity, which is also stable at elevated temperatures. The new cathode utilizes a conductive light-absorbing layer made of a mixture of metals and organic materials.