• Journal of the Korean Solar Energy Society
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• v.36 no.4
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• pp.11-20
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• 2016

For accurate wind resource assessment and wind turbine performance test, it is essential to secure wind data covering a rotor plane of wind turbine including a hub height. In general, we can depict wind speed profile by extrapolating or interpolating the wind speed data measured from a meteorological tower where multiple anemometers are mounted at different heights using a power-law of wind speed profile. The most important parameter of a power-law equation is a vertical wind profile exponent which represents local characteristics of terrain and land cover. In this study, we calculated diurnal vertical wind profile exponents of 8 locations in Jeju Island who possesses excellent wind resource according to the GUM (Guide to the Expression of Uncertainty in Measurement) to evaluate its uncertainty. Expanded uncertainty is calculated by combined standard uncertainty, which is the result of composing type A standard uncertainty with type B standard uncertainty. Although pooled standard deviation should be considered to derive type A uncertainty, we used the standard deviation of vertical wind profile exponent of each day avoiding the difficult of uncertainty evaluation of diurnal wind profile variation. It is anticipated that the evaluated uncertainties of diurnal vertical wind profile exponents at 8 locations in Jeju Island are to be registered as a national standard reference data and widely used in the relevant areas.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.384-387
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• 2006

Vertical L/UL (Load/Unload) velocity is very important parameter to determine the L/UL performance, and the vertical velocity is determined by the actuator velocity and the ramp profile. However, it is not easy to precisely control the actuator rotating velocity during the L/UL process. Especially in emergency parking, servo system doesn't operate, it is impossible to control an actuator velocity. Then, the vertical unloading velocity depends on only ramp profile. The ramp height and the sliding length for L/UL process in SFF (Small Form Factor) HDD are restricted due to slimness and small media. For these reasons, it is very difficult to design the ramp profile in SFF HDD. Therefore, this study analyzes the unloading dynamic characteristics for various ramp profiles and makes the thesis for ramp profile design.

• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.150-155
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• 2006

Vertical L/UL (Load/Unload) velocity is very important parameter to determine the L/UL performance, and the vertical velocity is determined by the actuator velocity and the ramp profile. However, it is not easy to precisely control the actuator rotating velocity during the L/UL process. Especially in emergency parking, servo system doesn't operate, it is impossible to control an actuator velocity. Then, the vertical unloading velocity depends on only ramp profile. The ramp height and the sliding length for L/UL process in SFF (Small Form Factor) HDD are restricted due to slimness and small media. For these reasons, it is very difficult to design the ramp profile in SFF HDD. Therefore, this study analyzes the unloading dynamic characteristics for various ramp profiles and makes the thesis for ramp profile design.

• Ocean Systems Engineering
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• v.2 no.4
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• pp.289-295
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• 2012

Assume fluid eddy viscosity in the vertical direction is parabolic. Sediment particles diffuse with the given fluid eddy viscosity. However, when the vertical diffusion coefficient profile is computed from the suspended sediment concentration profile, the coefficient shows lager values than the fluid mixing coefficient values. This trend was explained by using two sizes of sediment particles. When fine sediment particles like wash load are added in water column the sediment mixing coefficient looks much larger than the fluid mixing coefficient.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.71-78
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• 1990

This research was made to investigate the change of the image layer and of the vertical and horizontal magnification on the Panelipse radiographic image by the control of profile index. Using the Panelipse, a series of 60 exposures were taken with the steel balls placed in the holes of the plastic model plate, and then evaluated by 4 observers. Two points were assigned for a reading of sharp, one for middling sharp, and zero for unsharp. Each ball image then could be given a total reader score of 0 to 8. The author analyzed the image layer as defined by a sharpness score of 6 or more. The results obtained were as follows: As the profile index was increased, the shape of the image layer was not changed, and the width of the image layer was increased, and the position of the layer shifted away from the rotation center. As the profile index was increased, the ranges of vertical and horizontal magnification was increased, especially the ranges of horizontal magnification was greater than that of vertical magnification.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.1
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• pp.55-61
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• 2009

In this paper, a thrust prediction method for a developing vertical launching missile is proposed through considering a verified vertical launching missile(a baseline missile) as a model. In order to predict thrust profile of a developing vertical launching missile, both Similarity law and Pi theory are applied to the model. By comparing prediction results based on the 6-DOF program of a baseline missile with simulation results of a developing vertical launching missile, the proposed method has been indirectly verified.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.346-351
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• 2000

The study was carried out to investigate the characteristics of vertical velocity distribution measured by current meter at Kangkyung station in Keum river during the period of 1995 to 1997. It suggests the quadratic parabola equation to estimate the vertical velocity profile only from the measurement data of surface velocity. The equation was found to be statistically very stable and showed high significance to express the surface velocity and bottom velocity. The vertical velocity profile was determined by the relationships to the surface velocity, and a coefficient of the quadratic parabola equation. The vertical velocity profile can be applied to calculating the mean velocity and discharge, and to and to analyse the dispersion of pollutant materials in the streamflow.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.1 s.16
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• pp.13-21
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• 2005

Experiments on settling behaviour of fine-grained particles without destroying the large fragile aggregates were carried out in still water with a CCD (Charged Coupled Device)-Camera. The experiments dealt with the measuring of the vertical concentration profile of cohesive particles with a CCD-Camera and the physico-chemical influences (NaCl, density, temperature and pH value) on the vertical distribution of the concentration. The vertical concentration profile of fine suspended particles (alumina and quartz) was possible up to $20,000\;mg/{\ell}$ with a CCD-Camera. The vertical concentration profile of cohesive sediments was on the decrease because of the increasing initial concentration, temperature and salinity. The vertical concentration profile of alumina was on the decrease quicker than quartz with increasing salinity. Furthermore, the pH value affects the settling behaviour of alumina. At a PH value of 4.2 the settling rate of the particles was very low and on the increase until pH 8.9 because of the aggregation behaviour of particles. From the PH value of 9 the average settling velocity was on the decrease.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.119-138
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• 1998

Recently measurements of atmospheric trace gases from satellite are vigorous. So the development of its data processing algorithm is important. In this study, retrievalof vertical ozone profile from the atmospheric transmittance measured by satellite solar occultation method and its sensitivity to temperature and pressure are investigated. The measured transmittance from satellite is assumed to be given by the limb path transmittance simulated using annual averaged Umkehr data for Seoul. The limb path transmittance between wavelengths $9.89{\mu}m$ and $10.2{\mu}m$ is simulated with respect to tangent heights using the ozone data of HALOE SIDS(Hallogen Occultation Experiment Simulated Instrument Data Set) as an initial profile. Other input data such as pressure and temperature are also from HALOE SIDS. Vertical ozone profile is correctly retrieved from the measured transmittance by onion-peeling method from 50km to 11km tangent heights with the vertical resolution of 3km. The bias error of $\pm0.001$ in measured transmittance, the forced error of $\pm3K$ in each layer temperature, and the forced $\pm3%$ error in each layer pressure are assumed for sensitivity tests. These errors are based on the ADEOS/ILAS error limitation. The error in ozone amount ranges from -6.5% to +6.9% due to transmittance error, from -9.5% to +10.5% due to temperature error, and from -5.1% to +5.4% due to pressure error, respectively. The present study suggests that accurate vertical ozone profile can be retrieved from satellite solar occultation method. Accuracy of vertical temperature profile is especially important in the retrieval of vertical ozone profile.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.191-213
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• 1984

This study was made on the facial profile of the normal Korean children using the roentgenographic cephalograms. The subjects consisted 51 males and 47 females children of primary dentition with the normal occlusion and acceptable profile. For this study 13 soft tissue profile landmarks were plotted and 14 liner length, 9 soft tissue thickness, 8 vertical height length, 12 angles of soft tissue profile, and 2 vertical proportion were measured. The mean and standard deviations in the subjects were calculated and compared between male and female. The following results were obtained : 1. By the significant test, total facial convexity angle and soft tissue thickness were no significant difference between both sexes. 2. Lower facial height was greater than upper facial height in both sexes. 3. The vertical length of the upper and lower lips were 21.95 mm, 40.74 mm in male and 21.62 mm, 39.63 mm in female. 4. In the relationship of the upper lip and lower lip to the Ricketts' esthetic line, the male was 1.3 mm, 1.18 mm and the female was 1.16 mm, 1.27 mm front of the esthetic line. 5. Compared with the angulation of flush terminal plane group and mesial step group, the mesial step group was greater than the flush terminal plane group except the chin angle.