• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.372-376
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• 2018

The effects of off-state bias stress on the characteristics of p-type poly-Si TFT were investigated. To reduce the gate-induced drain leakage (GIDL) current, the off-state bias stress was changed by varying Vgs and Vds. After application of the off-state bias stress, the Vgs causing GIDL current was dramatically increased from 1 to 10 V, and thus, the Vgs margin to turn off the TFT was improved. The on-current and subthreshold swing in the aged TFT was maintained. We performed a technology computer-aided design (TCAD) simulation to describe the aged characteristics. The aged-transfer characteristics were well described by the local charge trapping. The activation energy of the GIDL current was measured for the pristine and aged characteristics. The reduced GIDL current was mainly a thermionic field-emission current.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.29-37
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• 2017

In this study, we analyzed the impacts of land surface characteristics on spatially and temporally distributed soil moisture values at the Yongdam and Soyang-river dam watersheds in 2014 and 2015. The soil moisture, NDVI (Normalized Difference Vegetation Index) and temperature values at the spatio-temporal scales were estimated using satellite-based MODIS (MODerate Resolution Imaging Spectroradiometer) products. Then the Pearson correlations between soil moisture and land surface characteristics (NDVI, temperature and DEM-digital elevation model) were estimated and analyzed, respectively. Overall, the monthly soil moisture values at the time step were highly influenced by the precipitation amounts. Also, the results showed that the soil moisture has the strong correlation with DEM while the temperature was inversely correlated with the soil moisture. However the monthly correlations between NDVI and soil moisture were highly varied along the time step. These findings indicated that water loss near the land surface are highly occurred by soil and plant activities as evapotranspiration and infiltration during the no/less precipitation period. But the high precipitation amounts reduce the impacts of land surface characteristics because of saturated condition of land surface. Thus these results demonstrated that soil moisture values are highly correlated with land surface characteristics. Our findings can be useful for water resources/environmental management, agricultural drought, etc.

• Animal Bioscience
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• v.34 no.4
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• pp.743-750
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• 2021

Objective: The objectives of this study were to explore the expression patterns of myosin heavy chain (MyHC) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of M. longissimus lumborum (LL), M. psoas major (PM), and M. semimembranosus (SM) from Chinese Luxi and Qinchuan cattle. Methods: Three major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem. Results: PM muscle had higher pH value, a* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of MyHC I mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05). Conclusion: According to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.469-475
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• 2006

In this paper, an optimal suspension system with preview of the road input is synthesized for a half tracked vehicle. The main goal of this research is to improve the ride comfort characteristics of a fast moving tracked vehicle in order to maintain the driver's driving capability. Several different kinds of preview control algorithms are evaluated with active or semi-active suspension systems. The road information estimated from the motion of the 1st road-wheel is adequate to make the best use of the preview control algorithm for tracked vehicles. The ride-comfort characteristics of the tracked vehicle are more dependent on pitching angular acceleration than heaving acceleration. The pitching motion is reduced by the suspension system with hard outer suspensions and soft inner suspensions. Simulation results show that the performance of sky-hook algorithms for ride comfort nearly follow that of full state feedback algorithms.

• Structural Engineering and Mechanics
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• v.24 no.4
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• pp.395-410
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• 2006

This paper reports the result of an investigation into wave propagation in orthotropic laminated piezoelectric cylindrical shells in hydrothermal environment. A dynamic model of laminated piezoelectric cylindrical shell is derived based on Cooper-Naghdi shell theory considering the effects of transverse shear and rotary inertia. The wave characteristics curves are obtained by solving an eigenvalue problem. The effects of layer numbers, thickness of piezoelectric layers, thermal loads and humid loads on the wave characteristics curves are discussed through numerical results. The solving method presented in the paper is validated by the solution of a classical elastic shell non-containing the effects of transverse shear and rotary inertia. The new features of the wave propagation in laminated piezoelectric cylindrical shells with various laminated material, layer numbers and thickness in hydrothermal environment and some meaningful and interesting results in this paper are helpful for the application and the design of the ultrasonic inspection techniques and structural health monitoring.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.145-150
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• 2017

This paper present a unified method of steady state performance analysis and limits characteristics of an autonomous three-phase self-excited induction generator (SEIG) driven by a wind turbine under different types of loads and speeds. The proposed method is based on a new mathematical function to solve for the real and imaginary components of the complex equation of the mathematical model. Performances limits, regulation and characteristics of different configurations will be thoroughly examined and compared. The proposed system will be modeled and simulated and the performance limits characteristics will be compared with variable speed and variable capacity.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.453-456
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• 2001

The thrust control characteristics of single-sided linear induction motor (SLIM) is achieved using PI controller in this paper. The trembling of air gap length between the primary winding and the secondary structure of the SLIM must be minimized in order to get quick response results. Also, the input voltage of SLIM is involved with the time harmonics because most SLIM is driven by inverter. According to the feedback linear control system, this paper describes with applying the non-linear control, speed and estimated flux algorithm. At the result of this experiment, we reached to the improvement of thrust characteristics with PI controller.

• Journal of electromagnetic engineering and science
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• v.5 no.2
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• pp.72-79
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• 2005

The leaky dispersion characteristics of a circular dielectric rod were investigated using Davidenko's method for several lower-order transverse magnetic(TM) modes. The normalized complex propagation constants were precisely determined and their tolerances below $10^{-10}$ compared with zero for both real and imaginary parts. It was also checked whether the normalized complex propagation constants obtained represented forward leaky waves. The leaky modes existing below the cutoff frequency of the guided mode were classified as a nonphysical mode, reactive mode, antenna mode, and spectral gap based on a precise determination of the complex propagation constants. Finally, the effects of the dielectric constant and radius of the dielectric rod on the leaky dispersion characteristics were also considered.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.158-161
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• 1991

A new analytical expression for the temperature variation characteristics of hydrogenerated amorphous silicon (a-si:H) thin film transistors, between 223K and 433K, is presented and experimentally virified. The result show that the experimental transfer and output characteristics at several temperatures are easily modeled between $-50^{\circ}C\;and\;90^{\circ}C$. The model is based on three function obtained from the experimental data of $I_D$ versus $V_G$. Theoretical results comfirm the simple form of the model in terms of the device geometry. It was determined that as the temperature increaseed, the saturated drain current increased.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1103-1109
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• 2010

In this paper in order to analyze the mechanical properties, the permeability and the freezing properties of SB-2 materials which are mainly used with the subbase materials on the rod. For this ends, a series of the physical test, the permeability test and the freezing test were carried out the samples mixed the small aggregate and the big aggregate from which was re-classified the SB-2. From the test results, it was analyzed the characteristics of permeability and the characteristics of freezing of the samples.