• Journal of the Optical Society of Korea
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• v.9 no.1
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• pp.6-12
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• 2005

The perturbation approach is applied to solve the nonlinear Schrodinger equation, and its valid range has been determined by comparing with the results of the split-step Fourier method over a wide range of parameter values. With γ= 2㎞/sup -1/mW/sup -1/, the critical distance for the first order perturbation approach is estimated to be(equation omitted). The critical distance, Z/sub c/, is defined as the distance at which the normalized square deviation compared to the split-step Fourier method reaches 10/sup -3/. Including the second order perturbation will increase Z/sub c/ more than a factor of two, but the increased computation load makes the perturbation approach less attractive. In addition, it is shown mathematically that the perturbation approach is equivalent to the Volterra series approach, which can be used to design a nonlinear equalizer (or compensator). Finally, the perturbation approach is applied to obtain the sinusoidal response of the fiber, and its range of validity has been studied.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.365-366
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• 2015

Shunt active power filter is a complete current source which can provide an effective and adjustable solution for elimination of harmonic currents in power system. Its performance depends on strategy employed in reference current generation, control technique and topology of converter used in the design.[1-2]. In this paper Three Phase Six switch Z-source rectifier with active power filtering capability based on instantaneous reactive power theory is described. Thanking to the theory power factor and THD value are significantly improved. Experiment results and conclusions are presented.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.47-48
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• 2015

본 논문에서는 낮은 암단락 시간으로 높은 직류전압 증폭율을 얻기 위하여, 기존의 QZSI에서 직류전원을 임피던스 네트워크 내로 이동시키면서 스위칭소자를 1개 더 사용한 변형 스위치 QZSI 회로를 제시하였다. 이 변형 스위치 QZSI에 대한 동작 해석과 함께 기존 QZSI과 성능을 비교하고, 32비트 DSP를 사용한 실험을 통하여 제시한 회로의 성능을 확인한다.

• Geomechanics and Engineering
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• v.15 no.6
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• pp.1183-1191
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• 2018

Reliability analysis is generally regarded as the most appropriate method when uncertainties are taken into account in slope designs. With the help of limit analysis, probability evaluation for three-dimensional rock slope stability was conducted based upon the Mote Carlo method. The nonlinear Hoek-Brown failure criterion was employed to reflect the practical strength characteristics of rock mass. A form of stability factor is used to perform reliability analysis for rock slopes. Results show that the variation of strength uncertainties has significant influence on probability of failure for rock slopes, as well as strength constants. It is found that the relationship between probability of failure and mean safety factor is independent of the magnitudes of input parameters but relative to the variability of variables. Due to the phenomenon, curves displaying this relationship can provide guidance for designers to obtain factor of safety according to required failure probability.

• Journal of Life Science
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• v.12 no.2
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• pp.57-60
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• 2002

Apoptosis of vascular smooth muscle cell is observed in the vascular diseases such as atherosclerosis and restenosis. The death of vascular smooth muscle cells can be induced by cytokines and activation of Fas-pathways. It is widely accepted that apoptosis occurs without inflammation. There are, however, reports that apoptosis is not silent. Vascular smooth muscle cells dying by Fas-pathway secreted inflammatory cytokines including monocyte chemoattractant protein-1. This study have investigated whether apoptosis is associated with potent inflammatory cytokine tumor tumor necrosis factor (TNF)-${\alpha}$. The cells which undergo apoptosis by expressing FADD in the absence of tetracycline expressed and secreted TNF-${\alpha}$. When the level of TNF-${\alpha}$ transcript was investigated, dying smooth muscle cells exhibited transcriptional activation of TNF-${\alpha}$. The data indicate that dying vascular smooth muscle cells contribute to inflammation by expressing inflammatory cytokines. The present study suggests that apoptosis could not be silent in certain pathological situations.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.151-158
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• 2016

It is important to analyze dimensional errors occurring during shipbuilding process. A ship is constructed by assembling blocks and installing outfits in assembled ship structure. Blocks and outfits have a main direction that has greater importance than other directions from the view point of dimensional error. Therefore, a main direction should have a greater weighting factor than other directions in order to achieve meaningful inspection results. In this paper, a modified point registration method based on iterative closest point (ICP) is proposed. In this method, a user determines one or two main directions among x, y, and z directions, and then each main direction is made to have a greater weighting factor than other directions. For points registration, mapping between measured points and design points are performed by the modified ICP in which weighting factor assigned to each main direction is considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.13-16
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• 1994

In this paper, xPb(Zn$_{1/3}Nb_{2/3}$)$O_3$-yPbTiO$_3$-zPbZrO$_3$-(0.5wt%)MnO$_2$ ceramics were fabricated by the mixed oxide method sintered at $1250^{\circ}C$ for 2[hr] and then the deielectric, electromechanical coupling factor($K_{p}$ and mechanical coupling factor(Qm) properties were investigated. In 0.1PZN-0.45PT-0.45PZsample, dielectric properties and electromechanical coupling factor were 829 and 29%. In the case of 0.5PZN-0.45PT-0.50PZ sample, that was 101 according to mechanical quality facotr. molphotropic phase boundary(MPB) certained area which $PbTiO_3$addition quatity 40∼50[㏖%].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.234-237
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• 2000

In this paper, the structural, dielectric and piezoelectric properties of the Pb[(S $b_{1}$2/N $b_{1}$2/)$_{0.035}$- $_Mn_{1}$3/N $b_{2}$3/)$_{0.065}$-(Z $r_{0.49}$, $Ti_{0.51}$)$_{0.90}$] $O_3$ ceramics were investigated with respect to the variation of the milling time. Grain size was decreased as the increase of milling time. As the milling time is increased, the particle size of the powder was decreased. Dielectric constant and electromechanical coupling factor (Qm)were slowly increased with the increase of milling time. The highest value of Qm was 1,497 at milling time 8 hour. Temperature coefficient of resonant frequency(TC $F_{r}$) was moved to positive side with the increase of milling time.e.e.e.e.e.e.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.454-459
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• 2007

In this work, micro-scale, high-performance solenoid-type RF chip inductors utilizing amorphous $Al_2O_3$ core material were investigated. The size of the chip inductors was $0.86{\times}0.46{\times}0.45mm^3$ and copper(Cu) wire with $27{\mu}m$ diameter was used as the coil. High frequency characteristics of the inductance(L), quality factor(Q), impedance(Z), and equivalent circuit parameters of the RE chip inductors were measured and analyzed using an RF impedance/material analyzer(HP4291B with HP16193A test fixture). It was observed that the RF chip inductors with the number of turns of 9 to 12 have the inductance of 21 to 34nH and exhibit the self-resonant frequency(SRF) of 5.7 to 3.7GHz. The SRF of inductors decreases with increasing the inductance and inductors have the quality factor of 38 to 49 in the frequency range of 900MHz to 1,7GHz.

• Journal of muscle and joint health
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• v.5 no.2
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• pp.174-190
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• 1998

Osteoporosis has been known as a common complication of rheumatoid arthritis and a major preventable health problem. Lots of studios have demonstrated that changes in life style can help delay or prevent osteoporosis. Therefore nursing intervention related osteoporosis prevention have consisted of education programs aimed at changing dietary and exercise habit. However knowledge gained from education haven't always leaded to behavior change. Therefore it is important to consider other psychological variables in effecting behavior change. Numerous research have found self efficacy and health belief to be an important factor in individual decision making behavior. The purpose of the study was to develop health belief and efficacy expectation promoting program based on Health Belief Model & Self Efficacy Model and to investigate its effects in women with rheumatoid arthritis. For this purpose, one group pretest-post design was used. The subject of the study were 16 women with rheumatoid arthritis in Pusan city and data collection was carried out from April, 1997 to May, 1998. The intervention program was consisted of educating on osteoporosis and enhancing and reinforcing self efficacy by verbal persuasion during the period of 4 weeks. The instruments were used to collect data in this study were Osteoporosis Health Belief Scale, Osteoporosis Self Efficacy Scale, and Osteoporosis Preventive Behavior Scale. Data was analyzed by Wilcoxon signed rank test using SPSS $PC^+$ program. The results are as follows : 1) The behavior should be increased after intervention was supported(Z=-3.5162, p=.0004, diet : Z=-3.2942, p=.0010, exercise). 2) The sub-hypothesis that perceived sensitivity should be increased after intervention was supported (Z=-2.3854, p=.0171). 3) The sub-hypothesis that perceived severity should be increased after intervention was rejected(Z=-1.4327, p=.1520). 4) The sub-hypothesis that perceived benefit should be increased after intervention was supported(Z=-2.6410, p=.0083). 5) The sub-hypothesis that perceived barrier should be decreased after intervention was supported (Z=-2.4138, p=.0158). 6) The sub-hypothesis that efficacy expectation should be increased after intervention was supported(Z=-3.5162, p=.0004). As a conclusion, it was found that health belief and self efficacy promoting program was an effective nursing intervention for preventing osteoporosis of rheumatoid arthritis.