• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.6
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• pp.545-550
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• 2013

We present a tactile information transceiver using a friction-tunable slider-pad. While previous tactile information devices were focused on either input or output functions, the present device offers lateral position/vertical direction detection and texture expression. In characterizing the tactile input performance, we measured the capacitance change due to the displacement of the slider-pad. The measured difference for a z-axis click was 0.146 nF/$40{\mu}m$ when the x-y axis navigation showed 0.09 nF/$750{\mu}m$ difference. In characterizing the texture expression, we measured the lateral force due to a normal load. We applied a voltage between parallel electrodes to induce electrostatic attraction in DC and AC voltages. We measured the friction under identical fingertip action conditions, and obtained friction in the range of 32-152 mN and lateral vibration in the force range of 128.1 mN at 60 V, 2 Hz. The proposed device can be applied to integrated tactile interface devices for mobile appliances.

• Research in Community and Public Health Nursing
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• v.16 no.4
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• pp.458-466
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• 2005

Purpose: The purpose of this study was to determine the relation between test anxiety and mental health in adolescents. Method: The subjects were 450 students of two academic high schools in J City, who were selected through convenient sampling. Data were collected through a survey using a structured questionnaire from September 1st to 15th 2005. Collected data were analyzed using SPSS 10.0 for Windows through descriptive analysis, Pearson's Correlation Coefficient, t-test, ANOVA, Scheffe's test and stepwise multiple regression. Result: The mean score of test anxiety was 2.40 (range:1.13-3.81) and that of mental health was 2.77 (range:0.64-5.03). A significant negative correlation was observed between test anxiety and mental health (r=-0.28, p=.000). Test anxiety was significantly different according to adolescents' general characters such as gender (t=-1.98, p=.048), grade (F=3.54, p=.030), school life satisfaction (F=10.73, p=.000) and relationship with the teacher (F=11.60, p=.000). Mental health was significantly different according to adolescents' general characters such as religion (t=2.14, p=.032) and school life satisfaction (F=4.13, p=.017). The most powerful predictor of mental health was test anxiety and it, combined with religion, accounted for 9.0% of variance in mental health in adolescents. Conclusion: Test anxiety and mental health was found to be in a significant negative correlation with each other in adolescents. Therefore, nursing intervention programs for adolescents needs to reduce their test anxiety to improve their mental health.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.639-643
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• 1995

The temperature dependence of the dark conductivity was studied on undoped hydrogenated amorphous germanium (a-Ge : H) over the range from 297 to 423 K. The pre-exponential factor $\sigma$$\_$0/ and activation energy E$\_$C/-E$\_$F/ are determined by an Arrhenius plot. The Arrhenius plot of the electrical conductivity shows a kink around the kink temperature and then is composed of two exponential functions. The obtained statistical shift ${\gamma}$$\_$F/ was about 8.65${\times}$10$\^$-3/eV/K and the pre-exponential factor $\sigma$$\_$0/ was about 2$\Omega$$\^$-1/cm$\^$-1/. A temperature dependent defect density is numerically calculated from the conductivity data. A change of the defect density is observed in the factor of about two in the range of the experimental temperature.

• Journal of the Korean Ceramic Society
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• v.41 no.8
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• pp.633-636
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• 2004

The sintering behavior, microstructure and microwave dielectric properties of Ca $Ti_{0.5}$F $e_{0.25}$N $b_{0.25}$ $O_3$ with CuO have been investigated. Among the range of additions, 3 wt％ CuO was observed to perform most satisfactory for acting as a sintering aid. The dielectric properties were found to strongly depend on the sintered densities. The dielectric constant increased with sintering temperatures, while the Q${\times}$ $f_{0}$ value affected by second phase. For Ca $Ti_{0.5}$F $e_{0.25}$N $b_{0.25}$ $O_3$ with 3 wt％ CuO sintered at 100$0^{\circ}C$ for 2 h, the dielectric properties with an $\varepsilon$$_{r}$ value of 56, a Q${\times}$ $f_{0}$ value of 3,500 GHz and a $\tau$$_{f}$ value of 10 ppm/$^{\circ}C$ were obtained and suggested for practical applications.cations.ons.ons.ons.

• Speech Sciences
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• v.15 no.1
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• pp.87-98
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• 2008

This study compares the pitch production of children using cochlear implants (CI) with that of children with normal hearing. Twenty subjects from six to eight years old participated in the study. Three kinds of sentences were read and analyzed using Visi-Pitch $\blacktriangleright$(KAY Elemetrics, Model 3300). There were no considerable differences between the two groups regarding pitch, mean fundamental frequency (F0) and pitch range. In the cases of the slope value of F0 and duration, however, there were significant differences. Thus, it is concluded that duration and pitch control can be crucial factors in determining the intonation treatment of the children with cochlear implants.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.23-32
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• 2014

This study presents the prosodic characteristics of 'Motherese' and 'Teacherese (child care teacher and kindergarten teacher)'. 21 mothers and 24 teachers spoke to children in the child care center or kindergarten. Children are in their 4;00-6;11. Speech and articulation rate, number of accentual phrases (APs), number of intonational phrases (IPs), pitch-related factors (f0, pitch range, f0 standard deviation), and intonation slope (mean Absolute, f0, q-tone slope) were measured. 2 groups spoke 2 sentential types (interrogative_ alternative question, declarative_ coordinated sentence) in 2 situations (one accompanied with the children, the other done without children, but pretending as if they were in front of the children). The results indicate that teachers show more noticeable prosodic characteristics than mothers do.

• Journal of IKEEE
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• v.17 no.3
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• pp.234-240
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• 2013

This paper presents an incremental delta-sigma analog-to-digital converter (ADC) for a single-electrode capacitive touch sensor. The second-order cascade of integrators with distributed feedback (CIFB) delta-sigma modulator with 1-bit quantization was fabricated by a $0.18-{\mu}m$ CMOS process. In order to achieve a wide input range in this incremental delta-sigma analog-to-digital converter, the shielding signal and the digitally controlled offset capacitors are used in front of a converter. This circuit operated at a supply voltage of 2.6 V to 3.7 V, and is suitable for single-electrode capacitive touch sensor for ${\pm}10-pF$ input range with sub-fF resolution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.535-536
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• 2008

Multi-layered thin films of ZnS/$Na_3AlF_6$/ZnS/Cr were deposited on glass substrate by evaporation process. ZnS and $Na_3AlF_6$ were selected as high and low refractive index material, and additionally Cr was chosen as mid reflective layer respectively. The multi-layered thin films were prepared in terms of different optical thickness and different staking sequence and layers. The optical properties were systematically characterized with different optical thickness of $Na_3AlF_6$ especially $0.25\lambda$ and $0.5\lambda$. In order to expect the experimental result, the simulation program, the Essential Macleod Program(EMP) was adopted. Based on the results taken by spectrophotometer at viewing angle $45^{\circ}$, the ZnS/$Na_3AlF_6$/ZnS/Cr multi-layered thin film shows purple colour range in $0.25\lambda$， bluish green in $0.5\lambda$, red purple in $0.75\lambda$, and purple in $1.0\lambda$ respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.231-236
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• 2013

This study was conducted to investigate the yield response of soybean to drought stress in 1984 and 1986 at the experiment field of the National Academy of Agricultural Science using experiment plots with different soil water tension and fertilizer levels. The average yield response factor (YRF) of soybean to evapotranspiration (ET) calculated as [(Ya/Ym)/(ETa/ETm)], where Ya, average yield; Ym, maximum yield; ETa, average ET; and ETm, maximum ET, was 0.91 with the range from 0.74 to 1.16. Relationship between yield index (YI=[Ya/Ym]) and evapotranspiration index (ETI=[ETa/PET]) was $YI=0.87{\cdot}(ETI)+0.09$. Relationship between YI and the maximum soil water tension (Hmax) was $YI=1.23-0.23{\cdot}{\log}$ (Hmax). Relationship between YI and the days of drought stressed (Dr) was $YI=0.877{\cdot}{\exp}$ ($-0.01{\cdot}Dr$). The relation between YI and fertilizer level (F) was $YI=-0.21{\cdot}F2+0.36{\cdot}F+0.33$, under very serious drought condition as the maximum soil water tension was 0.3 MPa.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.49-59
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• 2005

Turbulent heat transfer over a fully-developed wavy channel is investigated by a turbulence model. The nonlinear k- f - f$_{ model of Park et at.[1] is slightly modified and their explicit algebraic heat flux model is employed. The Reynolds number is fixed at Re$_{b}$=6760 and the wave configuration is varied in the range of 0 $\leq$ $\alpha$/$\lambda$$\leq$0.15 and 0.25 $\leq$A/H$\leq$4.0. In order to verify model performances, a large eddy simulation is performed for the selected cases. The model performance is shown to be generally satisfactory. By using k- $\varepsilon$ - f$_{ model, the enhancement of heat transfer and the characteristics of turbulent flow in wavy wall are investigated. Finally, the influence of wavy configuration on heat transfer is scrutinized.