• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.40-44
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• 2011

Recent studies in crystalline silicon solar cell fabrication have been focused on high efficiency and low cost. However, the rising of the cost results in additional processes to approach high efficiency. The fabrication process also becomes complicated with additional technologies. In this paper, we studied the selective emitter formation with phosphorous paste to improve the conversion efficiency. Selective emitter formations like two-step diffusion or etch-back method require at least one more step compared in the conventional line since heavily and lightly doped area was needed to form separately.However,one-step diffusion process is the method diffusing heavily and lightly doped area at the same time only with additional screen-printing step. This study lays the foundation for the simple way to form the selective emitter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.27-28
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• 2006

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1678-1685
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• 1993

This paper considers a time delay control of noncolocated flexible mechanical systems in discrete time domain. A stability criterion suggested in the previous paper is,extended in the consideration of infinite mode property of flexible systems and finite control sampling frequency. Based on the stability criterion, the one step advanced discrete time derivative control is suggested, which can stabilize infinite number of modes of a flexible system. The sensitivity analysis shows the robustness of the one step advanced control to the system parameter uncertainties and time delay errors. Application to a simply supported beam verifies the extended stability criterion and the effectiveness of the one step advanced D-control.

• Structural Engineering and Mechanics
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• v.15 no.1
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• pp.71-81
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• 2003

The governing differential equation for buckling of a one-step bar with the effect of shear deformation is established and its exact solution is obtained. Then, the exact solution is used to derive the eigenvalue equation of a multi-step bar. The new exact approach combining the transfer matrix method and the closed form solution of one step bar is presented. The proposed methods is convenient for solving the entire and partial buckling of one-step and multi-step bars with various end conditions, with or without shear deformation effect, subjected to concentrated axial loads. A numerical example is given explaining the proposed procedure and investigating the effect of shear deformation on the critical buckling force of a multi-step bar.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.13-34
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• 2008

In Headgear and Ornaments for Diadem in the Period of the Three States there was Conical Cap(or Pointed Cap), Feathered Cap(Trim), and Crown[Tree-typed Diadem and Tree and Antler-typed Diadem] was excavated from the tombs. Feathered Trim is 5 types, Feathered Trim I-A, Feathered Trim I-B, Feathered Trim II-A, Feathered Trim II-B, Feathered Trim II-C in according to upper part of central insert plate style. Feathered Trim I-A, I-B, II-B type was general style that was found in most of the old tombs in ancient Silla, Gaya. Feathered Trim II-A type was excavated from the only Silla tombs and II-C type was excavated from Gaya tombs. The Ornaments for Diadem in Baekje was excavated from the tombs is adorned with a arranged leaf-stems on either sides and the flower-shaped. They were distinguished with the original mode of Goguryeo and ancient Silla at the time. Tree-typed Diadem is five part in according to the Mountain(;山)-typed piled up. Only one Mountain(;山)-typed one in three stand-up ornament(I-1 type), and three step one in three stand-up one(I-2 type), modification one (I-3 type), three step one of four and five stand-up ones(I-4 type), and four step one of four and five stand-up ones (I-5 type). Tree and Antler-typed Diadem is three part in according to the step of Mountain(; 山)-typed and cross-shaped of the upper part. Three one of three step one of Mountain(;山)-typed and two Antler- typed (II-1 type), cross-shaped one(II-2 type), four step one(II-3 type).

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.484-485
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• 2006

The one step type pole and two step type pole are used in KEPCO's distribution system. The neutral current may occurs in three-phase four-wire distribution system due to unbalanced load. This paper presents neutral current both one step type pole and two step type pole in distribution system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.35-40
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• 2007

The one step type and two step type pole are used in distribution line. If the three phases are not balanced, the communication line can be damaged by induced voltage. This paper calculates the neutral current using KEPCO's distribution system model which is only composed by one step type pole. The used system model is modelled by using ATPDraw and the neutral current is calculated by using EMTP/MODELS. Many cases for abstracting the neutral current characteristics in KEPCO's distribution system are simulated and analyzed.

• Journal of the Korean Home Economics Association
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• v.35 no.5
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• pp.49-59
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• 1997

The purpose of this study is to classify of the Tree-typed and Tree and Antler-typed Diadem in old tombs of ancient Silla, Gaya. First, Tree-typed Diadem is four part in according to the Mountain(; 山)-typed piled up. Only one Mountain(; 山)-typed one in three stand-up ornament(I-1 Style), and three step one in three stand-up ones(I-4 S.). Three and Antler-typed diadem is three part in according to the step of Mountain(; 山)-typed and cross-shaped of the upper part. Three one of three step one of four step one(II-3 S.). They were influenced by Tree worship and cult of deer in Northern mounted nomadic groups.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1841-1851
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• 1990

Self-aligned gate GaAs MESFETs using ion beam deposited tungsten applicable to GaAs LSI fabrication process have been fabricated. Silicon implanted samples were annealed using isothermla two step RTA process and conventional one step RTA process. The electrical and physicla characteristics of annealed samples were investigated using Hall and I-V measurements. As results of measurements, activation characteristics of the isothermal two step RTA process are better than those of one step annealed ones. Using the developed processes, GaAs SAFETs (Self-Aligned Gate FET) have been fabricated and electdrical characteirstics are measured. As results, subthreshold currents of SAGFETs are 6x10**-10 A/\ulcorner, that is compatible to conventional MESFET, maximum transconductances of 0.75\ulcorner gate MESFET using one step RTA process and 2\ulcorner gate MESFET using isothermal two step RTA process are 18 mS/mm, 41 mS/mm respectively.

• 연구논문집
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• s.31
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• pp.65-75
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• 2001

A dynamic model of pump having one step gearbox and two step gearbox is developed by the lumped parameter method. The model accounts for shafts, ball bearings and journal bearings flexibilities, gyroscopic effects and the force couplings among the transverse and torsion motions due to gearing. Excitation forces of pump having one step gearbox and two step gearbox are considered as the mass unbalance of the rotors and gear transmission error which comes from the modified tooth surface. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered, shows that there are no critical speeds at the operating speeds. One step and two step gearboxes are manufactured and are estimated for vibration/noise, lubrication and performance.