• Child Health Nursing Research
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• v.21 no.4
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• pp.339-346
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• 2015

Purpose: This study was performed to explore the weight variations in high-risk term newborns hospitalized during the early postnatal period. Methods: A retrospective explorative study was performed with 64 term newborns who were hospitalized in the NICU after birth. Data on daily weight, birth information, and clinical features such as phototherapy, placements, nutritional status were reviewed through medical records for 14 days of life. General Linear Model, GLM was applied to analyze the weight variation by clinical features of these high-risk term newborns for 14 days of life. Results: Newborns at 40 weeks of gestation showed little weight loss during the few days after birth then steadily gained weight to 7.6% at the 14th day. Infants born at 37-39 gestation showed little weight gain for 14 days though the weight loss itself was not apparent. As well, return to birthweight was not observed in newborns with phototherapy, infants placed on a warmer or infants having gastrointestinal dysfunction for 14 days of life. Conclusion: Even for term newborns, physiologic weight loss may not be warranted even if newborn is born at less than 40 week of gestation, or with high-risk conditions that warrant admission to NICU.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.55-57
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• 2003

In this paper, we described the procedures of AC transport current loss in HTS tape. To carry out the calculation, A-$\Phi$ formulation was introduced and two dimensional FEM was used for computation. The results were showed that ellipse shape was higher loss compared to rectangle one and these were almost same behavior of analytical results predicted by Norris. A comparative analysis of loss for various n-value variation was also presented.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.315-317
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• 2007

This paper proposes a loss minimization algorithm for doubly-fed induction generator (DFIG) by controlling the stator reactive power. The proposed strategy directly controls the rotor current to achieve the operating point of minimum generator loss and maximum power point tracking. The maximum power is obtained by tracking the q-axis rotor current with generator speed variation and the minimum generator loss is achieved by controlling the d-axis rotor current. Experimental results are shown to verify the validity of the proposed scheme.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.213-220
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• 2002

The sound wave in the sea propagates under the effect of water depth, sound velocity structure, sea surface and bottom roughness, and bottom sediment distribution. In particular the sound velocity structure in shallow water varies with time and space, an? the sediment distributes very variedly with place. In order to investigate the seasonal variation of low-frequency sound propagation in the Yellow Sea, the propagation experiments were conducted along the same track in the middle part of the Yellow Sea at various seasons of spring. summer, and autumn. In this paper we consider the measurement results on the propagation loss with the sound velocity structure, and investigate the seasonal variation of the propagation loss. As a result, the propagation losses measured in summer were larger than the losses in spring and autumn. And the propagation losses measured in autumn were smaller than the losses in spring. The seasonal change of the propagation loss increased with the rise of sound frequency and the propagation range.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.822-825
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• 2002

A lot of rotating machinery are generally used in industrial field and the electrical machinery such as the motor and generator account for the most of the part. Generally motor and generator have electrical loss because of eddy current. So silicon steel sheets are used in order to reduce the electrical loss and furthermore laminated rotor is used for motor and generator to eliminate the electrical loss and heat generation. However, the more high speed, large scale and high precision of the system, the more important to estimate the critical speed. In this paper verifies the variation of the critical speeds in accordance with the variation of the pressing force of lamination plate for the rotor which is supported by ball bearing with the experimental data as well.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.2
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• pp.83-90
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• 2018

This paper describes a case study on the design factor analysis of vertical wind tunnel for skydiver's training or experiencing of paradropping exercise in the air. The case study of vertical wind tunnel design is to provide the knowledges on effects of parameter's variation when it is applied to overall or partial duct of tunnel circuit. The analysis of design parameters based on pressure loss are produced one by one through the tunnel components from the flight chamber because the wind tunnel must satisfy the requirement of flight chamber such as flow speed, quality and quantity. Results shows the various effects of parameter variation with pressure loss in the wind tunnel circuit. Pressure loss should be based on the determination of fan and power system which can be selected from market or new design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1991.10a
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• pp.3-6
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• 1991

CuInSe$_2$ films have been prepared by selenium vapor annealing of sputtered Cu/In layer. The properties of selenized CuInSe$_2$films have been studied as a function of selenization temperature for two sputtered thicknesses. A large indium loss occurs in the sputtered Cu/In layer during the selenization. The indium loss with the selenization temperature is confirmed by the increase in the amount of CuxSe phase at lower temperature and the decrease in the crystallinity of chalocpyrite CuInSe$_2$phase at higher temperature. The variations of the electrical properties in the selenized films with the selenization conditions are due primarily to the variation of hole concentration. The variation of the hole concentration can be explanined by the indium loss away the sputtered Cu/In layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.153-156
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• 2001

(Ba$_{0.6-x}$Sr$_{0.4}$Ca$_{x}$)TiO$_3$ (x=0.10, 0.15, 0.20) ceramics were fabricated by the mixed-oxide method and their dielectric properties were investigated with variation of composition ratio, doped ZrO$_2$ (0.5, 1.0, 1.5, 2.0, 3.0 wt%) and sintered at 145$0^{\circ}C$. The dielectric constant and loss of the x=0.10 specimen applied field were 19.86 and 0.302 % at 0 V/cm, and 25.937 and 0.339 % at 300 V/cm, respectively. Dielectric constant were increased with increased applied field and decreased with increased frequency, and dielectric loss were within 0.1% at applied 800 MHz, respectively. all specimens showed fairly good applied field. Although, dielectric constant and loss of all specimen showed to tend of nearly the same. same.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.3-7
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• 2009

A cylindrical pin fin with inside fluid is optimized based on fixed fin volume by using the one dimensional analytic method. Heat loss from the fin and the pin fin radius for fixed fin volume is presented as a function of the fin length. Temperature variation of the fin with the variation of ambient and inside fluid convection characteristic numbers and fin base thickness is listed. The maximum heat loss at the practical fin length and corresponding optimum fin length and radius are presented as a function of fin base thickness, inside convection characteristic number, fin volume and ambient convection characteristic number. One of the results shows that the optimum pin fin shape becomes relatively fatter as the fin volume increases.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.263-266
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• 1987

Generally an incandescent lamp is made in the bulb with a horizontal position filament. In this paper the position of filament was changed Into a vortical position. When the position of filament is changed into a vertical position, efficacy is increased and color rendering is somewhat improved. In this subject the heat loss by a filling gas is important. The heat loss by a filling gas was calculated theoretically. The results in an Incandescent lamp experiment can be analyzed through the heat loss by a filling gas. As a filling gas the mixture of argon and nitrogen is used. The variation of lamp characteristics by the shape of filament rill be considered. The change by filament position to a vortical position is required in the field of power consumption saving of lighting system.