• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.235-244
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• 2001

Liquefaction may be caused by sudden decrease in the soil strength under undrained conditions. This loss of soil strength is related to the development of excess pore pressures. During this study, fines content affects the maximum and minimum void ratios are investigated. The results of static and cyclic triaxial test on silty saturated sands are presented. These tests are performed to evaluate liquefaction strength and static and cyclic behavior characteristics. The samples are obtained from Saemangeum and drying on air. The main results are summarized as follows : 1) The maximum and minimum void ratio lines follow similar trends. 2) Maximum and minimum void ratios are established at 20~30% fines content. 3) As confining pressures and overconsolidation ratio are increased, the resistance to liquefaction are increased. 4) Instability friction angles are increased with increasing initial relative density. 5) The resistance to liquefaction are decreased with increasing effective stress ratio.

• ETRI Journal
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• v.31 no.3
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• pp.254-262
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• 2009

This paper presents a novel simple filter design method based on a parallel short-ended coupled-line structure with capacitive loading for size reduction and ultra-broad rejection of spurious passbands. In addition, the introduction of a cross-coupling capacitor into the miniaturized coupled-line can create a transmission zero at the second harmonic frequency for better frequency selectivity and attenuation level. The aperture compensation technique is also applied to achieve a strong coupling in the coupled-line section. The influence of using the connecting transmission line to cascade two identical one-stage filters is studied for the first time. Specifically, such a two-stage bandpass filter operating at 2.3 GHz with a fractional bandwidth of 10% was designed and realized with low-temperature co-fired ceramic technology for application in base stations that need high power handling capability. It achieved attenuation in excess of -40 dB up to $4f_0$ and low insertion loss of -1.2 dB with the size of 10 mm ${\times}$ 7 mm ${\times}$ 2.2 mm. The measured and simulated results showed good agreement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.373-376
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• 2009

A full rig combustor test and altitude ignition test were carried out for radial-annular combustor of micro turbojet engine. 11.2% total pressure loss and 99.85% of combustion efficiency were measured at design point of engine under sea level standard condition and $2{\sim}6$ of air excess ratio for ignition envelope was achieved on engine starting regime. Finally, A 30,000 ft high altitude ignition test was also performed and finally we found out that the developed radial-annular combustor is appropriate to micro turbojet engine.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.1
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• pp.25-32
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• 2017

In this paper, a fabrication method of low-loss tapered optical fibers coupler using hydrofluoric acid with surface tension driven is proposed. The proposed fabrication method is very simple compared to flame-based method, and shows low excess insertion losses compared to polishing method. The adiabatic-tapered structure along the coupling region of the coupler shows wavelength independent characteristic over the C-band in optical communication system, and will enable promising applications.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.44 no.7
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• pp.914-918
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• 1995

In this study, Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ (x=0.65, 0.52, 0.35) thin films were fabricated by Sol-Gel method. A stock solution with excess Pb 10[mol%] of Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ was made and spin-coated on the Pt/SiO$_{2}$/Si substrate at 4000[rpm] for 30[sec.]. Coated specimens were dried on the hot-plate at 400[.deg. C] for 10[min.]. Sintering temperature and time were 500~800[.deg. C] and 1~60[min.]. The coating process was repeated 6 times and the final thickness of the thin films were about 4800[A]. To investigate crystallization condition, PZT thin films were analyzed with sintering temperature, time and composition by the XRD. The microstructure of thin fulms were investigated by SEM. The ferroelectric perovskite phases precipitated under the sintering of 700[.deg. C] for 1 hours. In the PZT(52/48) composition, dielectric constant and dielectric loss were 2133, 2.2[%] at room temperature, respectively.ively.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.178-184
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• 1998

Optical fiber coupler is a crucial optical passive component for optical transmission systems. In this paper, we fabricate wavelength insensitive optical coupler(WIC), of two types for which the processing procedures are complicate and difficult. These couplers are fabricated by two optical fibers having either different fiber parameters or different cladding diameters. To clarify the validity, we measure the optical characteritics and compare to the data of theoretical simulation. The experiment results ref#eat that it has uniformity of about 1.0 dB and excess loss of less than 0.1 dB in the range of $1310{\pm}40nm\;and\;1550{\pm}40nm$.

• The Journal of Internal Korean Medicine
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• v.13 no.1
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• pp.167-180
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• 1992

This study has been carried out to investigate the cause and originative mechanism of vertigo by referring to 46 literatures. The results were as follows; 1. The 1st factors causing vertigo are exuberance of fire in the Liver (肝火偏亢). and ascending of Yang of Wind (風陽升動) resulting from thought excess (思慮太過) and melancholy (憂鬱). 2. The 2nd factors causing vertigo is a malnurtrient of the brain resulting from dispersion of the Liver function (肝血虛) and failure in ascending of the Clear Yang (淸陽不升) due to hemorrhage and so on. 3. The 3rd factors causing vertigo are failure in ascending to the Brain and deficiency of blood of the Liver (肝血虛) resulting from the injury of the essence of the Kidney (肝精虧損). 4. The 4th factors causing vertigo is a ascending of exogenous pathogenic factors (外邪) to the Brain on deficiency state. 5. The 1st factors causing vertigo are Stagnatum of clear Yang (淸陽不振) and pershing of Yang (亡陽) resulting from loss of water and damage of active thin body fluid (津氣虧損). 6. The obesity is beonged to excessiveness Symptom-Complex (實證) and the thin to deficiency Symptom-complex (虛證). 7. The vertigo is connective with the Live (肝), Spleen (脾) and the Kidney (腎), but among those, most intimative viscera is the Liver (肝).

• The Korean Journal of Nuclear Medicine
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• v.10 no.1
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• pp.55-60
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• 1976

Marked augmentation of urinary aldosterone excretion following furosemide administration was observed in previous experiment. In this study, author measured the changes of aldosterone secretion after furosemide administration in normotensive young volunteers with high sodium intake. After intravenous injection of $1.2-^3H-aldosterone$, urine samples were collected in course of time until 24 hours after the injection. Furosemide administration was done at 30 minutes prior to aldosterone injection. Specific activities of $^3H-aldosterone$ during and after diuresis were measured and aldosterone secretion rates were calculated dividing the doses by specific activities. Results were as followed 1. Furosemide resulted in a marked increase in urinary aldosterone excretion. 2. Furosemide lead to an increase in both sodium and potassium excretion. 3. Aldosterone secretion rate was also increased during furosemide diuresis, but the rate was smaller than that of urinary excretion. 4. Continuous modest increase in aldosterone secretion rate was shown after diuresis and total excess amount of aldosterone secretion for 24 hrs was equivalent to the amount of aldosterone excretion produced by diruesis. 5. Abrupt marked loss of circulating aldosterone produced by diuresis was supplemented by long lasting increase in secretion for over twenty four hours.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.1
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• pp.23-29
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• 2005

The facial cleft and duplicated maxilla are lire congenital anomaly. After Rushton and Walker had reported a unilateral facial cleft with excess tooth and bone formation in 1937, few authors described similar cases. The etiology of this anomaly is not well understood, but considered embryologically as a neurocristopathy. A neurocristopathy is defined as a condition arising from aberrations in early migration, growth and differentiation of neural crest cells. This aberrations result in facial malformation such as facial clefts and loss or duplication of facial structures. We experienced a male newborn baby with bilateral facial cleft and duplicated maxilla. The cleft was surgically corrected when he was 5 months old. The function and appearance of lip are improved. Duplicated maxilla will be surgically removed. We report this case with review of literatures.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.27 no.1
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• pp.53-72
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• 2001

Dry skin is caused mainly by the perturbation of stratum corneum lipids which affected by ageing, change of season, excess use of surfactant and the effect of disease like atopic dermatitis and psoriasis. Intercellular lipid structures in stratum corneum are responsible for the barrier function of mammalian skin. The major lipd classes that can be extracted from stratum corneum are ceramides, cholesterol and fatty acid, which make up approximately 50, 25, 10 percent of the stratum corneum lipid mass, respectively. Small amount of cholesterol sulfate, phospholipids, glycosylceramide and cholesterol esters are also present. Recent studies have shown that application of one or two these lipids to the perturbed skin delays barrier recovery; only equimolar mixtures allow normal recovery. We observed that barrier recovery rate was improved in hairless mouse by topical application of single neutral lipids (ceramide, free fatty acid, cholesterol) and lipid mixtures. Whereas the application of single lipid didn’t allows a significant enhancement comparing with normal barrier repair, the equimolar mixtures of 3 components(including synthetic pseudoceramide PC104) improved barrier repair, as assessed by the transepidermal water loss. At clinical study to the volunteers aged over sixty, skin dryness recuperated by the increase of moisture(capacitance) and the reduction of scaling. Utilization of physiologic lipid mixture containing natural ceramides or synthetic pseudoceramide could lead to new forms of topical therapy for the dryness and dermatoses(e.g., psoriasis, atopic dermatitis and irritant dermatitis).