• Journal of the Korean Ceramic Society
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• v.33 no.6
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• pp.672-678
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• 1996

The relationship between domain switching and acoustic emission (AE) during poling was investigated using the tetragonal ferroelectric ceramics with composition of (Pb,La)TiO3+0.01MnO2 The amount of AE generation during poling increased with increasing dc electric field and raising temperature. It was confirmed that the change of the amount of AE generation with poling condition resulted from the difference of the amount of 90$^{\circ}$ domain switching and total amount of AE generation for 10 minutes was approximately proportional to the amount of 90$^{\circ}$domain switching. The A generations of two specimens which have different tetragonality rations(c/s rations) 15 at% and 24at% La-doped were also investigated. The sample with c/a ratio of 1.012 where 90$^{\circ}$ domains are dominate had larger amount of AE generation and 90$^{\circ}$ domain switching compared with the sample with c/a ratio of 1.004 where 180$^{\circ}$ domains are dominant.

• Asia-Pacific Journal of Business
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• v.3 no.1
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• pp.1-9
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• 2012

The Index of Learning Styles (ILS) instrument based on the Felder-Silverman Learning Style Model was used to determine distribution of learning styles of 125 South Korean business students enrolled in a South Korean institution of higher education. Results show that greater proportion of South Korean business students surveyed in this study prefer sensing over intuitive, visual over verbal, reflective over active, and global over sequential learning styles. The majority of business students have a balanced learning style in all four dimensions of the Felder-Silverman model. Among the students that do not have a balanced learning style, students with sensing, visual, reflective, and global learning styles dominate. Gender difference in learning style preference was not statistically significant for any of the four dimensions.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.471-484
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• 1994

The forest vegetation types and their structural characteristics in Mt. $Mud\v{u}ng$ were investigated by classification method and ordination method. The forest was classified into 7 communities by ristic composition table: Quercus monogolica community, Q. serrata community, Q.acutissima community, Q.variabilis community, Q.dentata community, Pinus densiflora community and Frainus mandshurica community. Considering the moisture gradient, two kinds of distributuin pattern were shown as follows; F. mandshurica, Q. acturissima, Platycarya strobilacea and Staphylea bumalda were distribute at moist habitats, while Q. monogolica, P. densiflora and Q.variabilis at dry habitats. In continuum analysis, each population occupied different distribution area but it was continuously overlapped. On the successional trends of tree species, it is postulated that Q. mongolica species might dominate the altitudinal zone over 700m.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1080-1084
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• 1989

The motion of an workpiece to be manipulated is determined by the forces applied to the workpiece. During the contact between the robot hand and the workpiece, impulsive forces may dominate all other forces, and determine the ultimate success or failure of a task. Therefore, one of the important problems in the robot hands is the control of the initial impact force. In this paper, the problem of the force control of robot hand under system with contact force is presented. The principle of energy can be applied in the modelling of the impact force. In order to achieve stable contact and avoid bounces and vibrations, VSS is adopted in the design of the contact force controller. Some simulations are carried out for a pushing operation to control the contact force.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.687-690
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• 2003

Experimental results are presented for gate oxide degradation and its effect on device parameters under negative and positive bias stress conditions using NMOSFET's with 3 nm gate oxide. The degradation mechanisms are highly dependent on stress conditions. For negative gate voltage, both hole- and electron-trapping are found to dominate the reliability of gate oxide. However, with changing gate voltage polarity, the degradation becomes dominated by electron trapping. Statistical parameter variations as well as the "OFF" leakage current depend on those charge trapping. Our results therefore show that Si or O bond breakage by electron can be another origin of the investigated gate oxide degradation.gradation.

• BMB Reports
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• v.31 no.5
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• pp.444-452
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• 1998

The visible spectra of soybean ferric leghemoglobin reductase exhibited a charge transfer band at 530 nm under aerobic condition. Spectra of the oxidized enzyme show a flavin peak at 454 nm and the enzyme has three redox states associated with the active site of the enzyme. The enzyme has an active disulfide bridge and two-electron transfer may dominate in the ferric state of leghemoglobin reduction. The midpoint potentials of the enzyme were determined by spectrotitration to be -0.294 V for disulfide/dithiol and -0.318 V for FAD/$FADH_2$. Since the midpoint potentials for $NAD^+$/NADH and the ferrous/ferric states of leghemoglobin are -0.32 V and +0.22 V, respectively, it is proposed that two electrons are transferred sequentially from NADH to FAD, to the disulfide group, and then to the ferric state of leghemoglobin in the enzyme reaction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.987-992
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• 1997

Burrs always come out with the machining of ducterial with small size. Though the size of burrs is small, burrs dominate deterioration of the accuracy of the micro grooves. So the burr generation model especially side burr generation model was investigated to predict the size of the burrs at the given cutting conditions. The side shear plane is introduced to build the burr generation model and the width of side shear plane nomalized with cutting depth is defined with the shear angle. From the theoretical observation, the width of side shear plane can vary up 40% of the cutting depth. To determine the size of burr and stiffness, single groovings were carried out and it was found that there exist a critical depth of cut that the size or stiffness of the burr vary.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.723-728
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• 2001

Wind flow perturbations, recirculations and turbulence generated by buildings often dominate air pollutant distributions around buildings. This paper describes dispersion of contaminants in the vicinity of a building by solving the concentration equation based on previously simulated wind flow field. Turbulence closure is achieved by using the standard k-e two-equation model. The paper shows application of the CIP method for solving a species concentration equation of contaminant gas around a rectangular building for two different sources under conditions of neutral atmospheric stratification. Results have been compared to the experimental data and the previous numerical results by hybrid scheme. The computational results of concentration profiles by the CIP method agree well with experimental data.

• Honam Mathematical Journal
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• v.25 no.1
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• pp.95-115
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• 2003

Consider the problem of estimating a $p{\times}1$ mean vector ${\theta}(p{\geq}4)$ under the quadratic loss, based on a sample $X_1,\;{\cdots}X_n$. We find an optimal decision rule within the class of Lindley type decision rules which shrink the usual one toward the mean of observations when the underlying distribution is that of a variance mixture of normals and when the norm $||{\theta}-{\bar{\theta}}1||$ is known, where ${\bar{\theta}}=(1/p)\sum_{i=1}^p{\theta}_i$ and 1 is the column vector of ones. When the norm is restricted to a known interval, typically no optimal Lindley type rule exists but we characterize a minimal complete class within the class of Lindley type decision rules. We also characterize the subclass of Lindley type decision rules that dominate the sample mean.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4392-4396
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• 2011

Porous silicon with a complex network of nanopores is utilized for photoelectrochemical energy conversion. A novel electroless Pt deposition onto porous silicon is investigated in the context of photoelectrochemical hydrogen generation. The electroless Pt deposition is shown to improve the characteristics of the PS photoelectrode toward photoelectrochemical $H^+$ reduction, though excessive Pt deposition leads to decrease of photocurrent. Furthermore, it is found that a thin layer (< 10 ${\mu}m$) of porous silicon can serve as anti-reflection layer for the underlying Si substrate, improving photocurrent by reducing photon reflection at the Si/liquid interface. However, as the thickness of the porous silicon increases, the surface recombination on the dramatically increased interface area of the porous silicon begins to dominate, diminishing the photocurrent.