• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.1
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• pp.11-16
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• 2001

CuNi alloy films are deposited by co-sputtering of dual targets (Cu and Ni, respectively). Effects of the co-sputtering conditions, such as powers applied to the targets, deposition pressures, and substrate temperatures, on the structural and electrical properties of deposited films are systematically investigated. The composition ratio of Ni/Cu is almost linearly decreased by increasing the DC power applied to the Cu target from 25.6 W to 69.7 W with the RF power applied to the Ni target unchanged(140 W). it is noted that the chamber pressure during deposition and the film thickness give rise to a change of the Ni/Cu ratio within the films deposited. The former may be due to a higher sputtering yield of Cu atom and the latter due to the re-sputtering phenomenon of Cu atoms on the surface of deposited film. The film deposited at higher pressures or at lower substrate temperatures have a smaller crystallite size, a higher electrical resistivity, and much more voids. This may be attributed to a lower surface mobility of sputtered atoms over the substrate.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.315-320
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• 2022

With the rapid development of urbanization the problems of pedestrian-level wind comfort and natural ventilation of tall buildings are becoming increasingly prominent. The velocity at the pedestrian level ($\overline{MVR}$) and variation of wind pressure coefficients $\overline{{\Delta}C_p}$ between windward and leeward surfaces of tall buildings were investigated systematically through numerical simulations. The examined parameters included building density ρ, height ratio of building α_H, width ratio of building α_B, and wind direction θ. The linear and quadratic regression analyses of $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were conducted. The quadratic regression had better performance in predicting $\overline{MVR}$ and $\overline{{\Delta}C_p}$ than the linear regression. $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were optimized by the NSGA-II algorithm. The LINMAP and TOPSIS decision-making methods demonstrated better capability than the Shannon's entropy approach. The final optimal design parameters of buildings were ρ = 20%, α_H = 4.5, and α_B = 1, and the wind direction was θ = 10°. The proposed method could be used for the optimization of pedestrian-level wind comfort and natural ventilation in a residential area.

• Clinical and Experimental Pediatrics
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• v.57 no.9
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• pp.403-409
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• 2014

Purpose: Although high morning blood pressure (BP) is known to be associated with the onset of cardiovascular events in adults, data on its effects in children with hypertension are limited. Our retrospective study aimed to define the clinical characteristics of children with morning hypertension (MH) and to determine its associated factors. Methods: We reviewed 31 consecutive patients with hypertension, confirmed by the ambulatory blood pressure monitoring (ABPM). We divided these patients into 2 groups: the MH group (n=21, 67.7%), morning BP above the 95th percentile for age and height (2 hours on average after waking up) and the normal morning BP group (n=10, 32.3%). We compared the clinical manifestations, laboratory results, and echocardiographic findings including left ventricular hypertrophy (LVH) between the groups. Results: The early/atrial (E/A) mitral flow velocity ratio in the MH group was significantly lower than that in the normal morning BP group. In addition, LV mass was higher in the MH group than in the normal morning BP group, although the difference was not statistically significant. The age at the time of hypertension diagnosis was significantly higher in the MH group than in the normal morning BP group (P =0.003). The incidence of hyperuricemia was significantly higher in the MH group than in the normal morning BP group. Conclusion: Older patients and those with hyperuricemia are at higher risk for MH. The rise in BP in the morning is an important factor influencing the development of abnormal relaxation, as assessed by echocardiography. Clinical trials with longer follow-up periods and larger sample sizes are needed to clarify the clinical significance of MH.

• Journal of Korean Association for Spatial Structures
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• v.2 no.1 s.3
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• pp.85-92
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• 2002

Two way grid single-layer domes are of great advantage in fabrication and construction because of the simple fact that they have only four members at each junction. But, from a point of view of mechanics, the rectangular latticed pattern gives rise to a nonuniform rigidity-distribution in the circumferential direction. If the equivalent rigidity is considered in the axial direction of members, the in-plane equivalent shearing rigidity depends only on the in-plane bending rigidity of members and its value is very small in comparison to that of the in-plane equivalent stretching rigidity. It has a tendency to decrease buckling -strength of dome considerably by external force. But it is possible to increase buckling strength by the use of roofing covering materials connected to framework. In a case like this, shearing rigidity of roofing material increases buckling strength of the overall structure and can be designed economically from the viewpoint of practice. Therefore, the purpose of this paper, in Lamella dome and rectangular latticed dome that are a set of 2-way grid dome, is to clarify the effects of roofing covering materials for increasing of buckling strength of overall dome. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. In case of Lamella domes which have nearly equal rigidity in the direction of circumference, the rigidity of roofing covering materials does not have a great influence on buckling-strength, but in rectangular latticed domes that has a clear periodicity of rigidity, the value of its buckling strength has a tendency to increase considerably with increasing rigidity of roofing covering materials 2. In case of rectangular latticed domes, as rise-span-ratio increases, models which is subjected to pressure -type-uniform loading than vertical-type-uniform loading are higher in the aspects of the increasing rate of buckling- strength according to the rate of shear reinforcement rigidity, but in case of Lamella dome, the condition of loading and rise-span-ratio do not have a great influence on the increasing rate of buckling strength according to the rate of shear reinforcement rigidity.

• Journal of Acupuncture Research
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• v.32 no.2
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• pp.131-145
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• 2015

Objectives : The purpose of this study was to demonstrate the effectiveness and availability of salt pharmacopuncture of Korean sun-dried salt and processing salt on the basis of bibliographical review. Methods : This study was done through a narrative review of related bibliography including medical books, journals, general bibliography, and web sites. Results : 1. Korean sun-dried salt is produced in the ground with soil, tiles, and pottery. Sun-dried, traditional, granulated, bamboo, and grilled salts are all appropriate for medical use. They are composed of a lower level of NaCl and unnecessary substances, and have a higher water and mineral content. 2. The 9~30 g of NaCl included in the physiological saline matches the ratio of a normal human body. However, if the saline is used for water supply, it should be improved because the recommended amount is much lower. 3. Medicine that includes NaCl is applied for lessening the congestion of the nasal cavity, alleviating cornea swelling, or for a lack of water. NaCl can also be used for washing contact lenses as well as cleaning the mucous membrane of the eyes and nose. 4. Salt relieves anger, detoxifies, induces vomiting, builds strong muscles and bones, gives energy, slows aging, and ultimately improves health. 5. Salt treats many diseases including: cardiovascular, hematosis, respirometer, obstetric, musculoskeletal, mineral supplement, eye, teeth and skin issues, etc.. However, salt is not used for treating asthma, cough, or other ailments mainly affecting the vascular system. 6. While NaCl in salt absorbs water and the vascular constriction results in higher blood pressure, the pressure induced from salt is actually a physiologically temporary rise. Rather, salt helps remove oil from the body and its potassium lowers blood pressure. Conclusions : It was suggested that salt pharmacopuncture of Korean sun-dried salt and processing salt should be made available for adjusting the physiological salt concentration and control of the Na side effects, therefore it would be useful in the treatment of diseases.

• Geomechanics and Engineering
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• v.32 no.2
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• pp.145-157
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• 2023

This paper aims at investigating the face stability of large-diameter underwater shield tunnels considering seepage in soft-hard uneven strata. Using the kinematic approach of limit upper-bound analysis, the analytical solution of limit supporting pressure on the tunnel face considering seepage was obtained based on a logarithmic spiral collapsed body in uneven strata. The stability analysis method of the excavation face with different soft- and hard-stratum ratios was explored and validated. Moreover, the effects of water level and burial depth on tunnel face stability were discussed. The results show the effect of seepage on the excavation face stability can be accounted as the seepage force on the excavation face and the seepage force of pore water in instability body. When the thickness ratio of hard soil layer within the excavation face exceeds 1/6D, the interface of the soft and hard soil layer can be placed at tunnel axis during stability analysis. The reliability of the analytical solution of the limit supporting pressure is validated by numerical method and literature methods. The increase of water level causes the instability of upper soft soil layer firstly due to the higher seepage force. With the rise of burial depth, the horizontal displacement of the upper soft soil decreases and the limit supporting pressure changes little because of soil arching effect.

• Food Science and Preservation
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• v.16 no.5
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• pp.669-674
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• 2009

We prepared puffed instant Nuroong-gi samples using a microwave and investigated the physicochemical characteristics of the products. The quality of Nuroong-gi prepared using a microwave was compared with that of noodles prepared in a steam cooker and pressure cooker in terms of moisture content, color, water binding capacity ratio, viscosity, sedimented volume of insoluble solids, turbidity, and sensory evaluation. The moisture content of Nuroong-gi prepared in a microwave was similar to that of steam cooker and pressure cooker samples. The color (lightness) of steam cooker-prepared noodles was greater than that of noodles cooked using other modes. The water binding capacity ratio fell with increasing microwave cooking time. The viscosity of noodles prepared using a microwave was higher than that of pressure cooker samples and lower than that of steam cooker noodles. The sedimented volume of insoluble solids and turbidity increased with a rise in cooking temperature. Nuroong-gi prepared in a microwave scored higher in sensory evaluation tests than did steam cooker or pressure cooker samples. These results indicate that Nuroong-gi preparation using a microwave is very efficient.

• Journal of Environmental Science International
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• v.14 no.10
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• pp.919-928
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• 2005

This study introduces the development of new supercritical water oxidation(SCW)(multiple step oxidation) to destruct recalcitrant organic substances totally and safely by using sodium nitrate as an oxidant. This method has solved the problems of conventional SCW, such as precipitation of salt due to lowered permittivity, pressure increase following rapid rise of reaction temperature, and corrosion of reactor due to the generation of strong acid. Destruction condition and rate in the supercritical water were examined using Polyvinyl Chloride(PVC) and ion exchange resins as organic substances. The experiment was carried out at $450^{\circ}C$ for 30min, which is relatively lower than the temperature for supercritical water oxidation $(600-650^{\circ}C)$. The decomposition rates of various incombustible organic substances were very high [PVC$(87.5\%)$, Anion exchange resin$(98.6\%)$, Cationexchange resin$(98.0\%)$]. It was observed that hetero atoms existed in organic compounds and chlorine was neutralized by sodium (salt formation). However, relatively large amount of sodium nitrate (4 equivalent) was required to raise the decomposition ratio. For complete oxidation of PCB was intended, the amount of oxidizer was an important parameter.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.371-376
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• 2001

The operating point of a small-sized axial fan for refrigerator is strongly dependent upon the system resistance. Therefore, the turbulent flow characteristics around a small-sized axial fan may change significantly according to the operating point. This study represents three-dimensional turbulent flow characteristics around a small-sized axial fan measured at the four operating points such as $\varphi=0.1$, 0.18, 0.25 and 0.32 by using fiber-optic type LDA system. This LDA system is composed of a 5 W Argon-ion laser, two optics in back-scatter mode, three BSA's, a PC, and a three-dimensional automatic traversing system. A kind of paraffin fluid is utilized for supplying particles by means of fog generator. Mean velocity profiles downstream of a small-sized axial fan along the radial distance show that both the streamwise and the tangential components exist predominantly in downstream except $\varphi=0.1$ and have a maximum value at the radial distance ratio of about 0.8, but the radial component, which its velocity is relatively small, is acting role that only turns flow direction to the outside or the central part of axial fan. Moreover, all of the velocity components downstream at $\varphi=0.1$ show much smaller than those upstream due to the static pressure rise at the low-flowrate region.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.7 no.1
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• pp.46-56
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• 1995

Three Pressure type wave gauges were installed for about 10 days for the analysis of long wave agitations in Mukho Harbor. Helmholtz and second resonant periods of seiche in Mukho Harbor are shown to be approximately 10.0-14.3 and 3.3 minutes from the spectral analysis of measured wave data. Amplification ratio at Helmholtz period reaches about 6.8 and the wave amplitudes in the harbor were in the range of 5-10 cm during the measurement period. Helmholtz and second resonant periods of seiche in Mukho Harbor agree very well with those computed using Jeong dt al. (1993b)'s model. The model gives rise to the first and third resonant peaks at 7.5 and 1.9 minutes, respectively.