• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.238-242
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• 2000

In this paper, the method for dielectric constant and less tangent measurements of microwave substrates using a microstrip line is presented. The two samples of an open-ended line and a short-ended tine are made and complex propagation constant is evaluated from the one-port scattering parameter measurements. This method has been automated fully using a personal computer and a vector network analyzer.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.4
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• pp.329-337
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• 1993

Improvement of orthognathic surgical techniques make it possible to design esthetic surgical correction for total esthetic face. In order to find the esthetic line which guide esthetic surgical correction in patients of orthognathic surgery, cephalometric soft tissue analysis of esthetic faces were performed. In esthetic Korean young adults, 25 males and 25 females who were within 1 S.D. of E-line, ANB, P/A facial height ratio, were analyzed in natural position keeping their face eye level. 1. Sn position is constant in males and females. The Sn-N'-N' Vertical plane angle is $5.3^{\circ}$ in both sexes. Sn is positioned in front of 5 mm in female 7 mm in male from the N' vertical plane. 2. The Sn-Ls line make constant angle to horizontal plane with $72.5^{\circ}$ in both sexes, which is called "upper esthetic line". The Ls-Pg' line makes constant angle to $72.4^{\circ}$ (range $72.2^{\circ}$ in female to $72.6^{\circ}$ in male), which is called "lower esthetic line". 3. When inter-esthetic line angle (the Sn-Ls line to Ls-Pg' line) has $144.9^{\circ}$, lower third face has esthetic upper and lower lip. 4. In treatment planning, Sn is first corrected in proper position, and then upper and lower esthetic line are established with the angle of 144.9. The maxilla is moved to tangent Ls to the upper esthetic line, and mandible is moved to tangent Li and Pg' to the lower esthetic line, according to the "y"-shaped esthetic lines, then lower third face showes esthetics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.38-46
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• 2012

In this paper, the necessity for the identification of the absolute phase value is introduced and analyzed for a particular conductor line of a 3-phase type distribution network and the recent methods are also introduced. For the determination of the exact phase value for a specific point in the line, as compared with the phase reference point, the measured phase value must be within a range of ${\pm}60[^{\circ}]$. However, the phase of a particular point can fluctuate depending on the line constant, transformer wiring method, line length, line amperage, etc. A theoretical formulation such as Simulink modeling and analysis for a distribution network are conducted for the identification of phase at a specific point in the line. In particular, through evaluating the effects of unbalanced current loads at the time of determination of the phase value, the limitations of the present method for the determination of phases is described.

• Geomechanics and Engineering
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• v.30 no.3
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• pp.219-231
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• 2022

Geotechnical materials such as silt, fine sand, or coarse granular soils may be unstable under undrained shearing or during rainfall infiltration starting an unsaturated state. Some researches are available describing the instability of coarse granular soils in drained or undrained conditions. However, there is a need to investigate the instability mechanism of unsaturated silty soil considering the effect of degree of compaction and net confining stress under partially and fully drained conditions. The specimens in the current study are compacted at 65%, 75%, & 85% degree of compaction, confined at pressures of 60, 80 & 120 kPa, and tested in partially and fully drained conditions. The tests have been performed in two steps. In Step-I, the specimens were sheared in constant water content conditions (a type of partially drained test) to the maximum shear stress. In Step-II, shearing was carried in constant suction conditions (a type of fully undrained test) by keeping shear stress constant. At the start of Step-II, PWP was increased in steps to decrease matric suction (which was then kept constant) and start water infiltration. The test results showed that soil instability is affected much by variation in the degree of compaction and confining stresses. It is also observed that loose and medium dense soils are vulnerable to pre-failure instability i.e., instability occurs before reaching the failure state, whereas, instability in dense soils instigates together with the failure i.e., failure line (FL) and instability line (IL) are found to be unique.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.2
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• pp.51-65
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• 2011

We compared a CONWIP(constant work-in-process) system with a kanban system in a production line with constant processing times. Based on the observation that a WIP-controlled line production system such as CONWIP and kanban is equivalent to a m-node tandem queue with finite buffer, we applied a max-plus algebra based solution method for the tandem queue to evaluate the performance of two systems. Numerical examples with 6 workstations were used to demonstrate the proposed analysis. The numerical results support the previous studies that CONWIP outperforms kanban in terms of expected waiting time and WIP. Unlike the kanban case, sequencing workstations in a CONWIP does not affect the performance of the system.

• ETRI Journal
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• v.27 no.2
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• pp.172-180
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• 2005

Image resampling according to epipolar geometry is an important prerequisite for a variety of photogrammetric tasks. Established procedures for resampling frame images according to epipolar geometry are not suitable for scenes captured by line cameras. In this paper, the mathematical model describing epipolar lines in scenes captured by line cameras moving with constant velocity and attitude is established and analyzed. The choice of this trajectory is motivated by the fact that many line cameras can be assumed to follow such a flight path during the short duration of a scene capture (especially when considering space-borne imaging platforms). Experimental results from synthetic along-track and across-track stereo-scenes are presented. For these scenes, the deviations of the resulting epipolar lines from straightness, as the camera's angular field of view decreases, are quantified and presented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.5
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• pp.21-30
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• 1973

A snaked-line array antenna is investigated for the use of high gain antenna at X-band frequency by studing its attenation constant and the radiation pattern. Attenuation constant which is equivalent to the radiation resistance varies roughly as a function of the square of sinh$\theta$a where sin$\theta$a corresponds to the amplitude of sinusoidal form of snaked-line. The directivity is determined by the number of snaked-line antennas and the periodic units of a snaked line.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.201-208
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• 1999

This paper presents the degradation of the system performance according to the vmiation of the rotor time constant. The algorithm for the on-line estimation of rotor time constant is proposed. which is applied to the consistent relationship between the tangent torque angle of the synchronous reference frame and that of stationary reference f frame. For the purpose of the validity of proposed algorithm. the computer simulation and the experiments have been p performed.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.113-118
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• 2003

The proposed rotor time constant estimation method can be applied to the direct vector control system of induction motor with flux observer In this paper the flux observer proposed by Gopinath model are used. This paper presents a new scheme for on-line estimation of rotor time constant using estimated rotor flux phase and current model rotor flux phase. The major advantage of this method are its dynamic correction capability, simplicity and accuracy as well as independence from change in motor parameter. simulation results are presented which demonstrate the effectiveness of the on line rotor time constant estimation.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.225-229
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• 1998

If there is a mismatch between the controller programmed rotor time constant and the actual time constant of motor, the decoupling between the flux and torque is lost in an indirect rotor field oriented control. This paper presents a new estimation scheme for rotor time constant using artificial neural networks. The parameters of induction motor model organize 2 layer neural to be weight between neuron, which is proposed new in this paper. This method makes networks simple, so its brings not only the improvement in speed but simplification in calculation. Furthermore, it is possible to estimated rotor time constant real time through on-line learning without using off-line learning. The digital simulation and the experimental results to verify the effectiveness of the new method are described in this paper.