• Wind and Structures
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• v.4 no.6
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• pp.481-494
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• 2001

Wind tunnel pressure tests were conducted on a 1:100 scale model of a large industrial building with solar panels mounted parallel to the flat roof. The model form was chosen to have the same aspect ratio as the Texas Tech University test building. Pressures were simultaneously measured on the roof, and on the topside and underside of the solar panel, the latter two combining to produce a nett panel pressure. For the configurations tested, varying both the lateral spacing between the panels and the height of the panels above the roof surface had little influence on the measured pressures, except at the leading edge. The orientation of the panels with respect to the wind flow and the proximity of the panels to the leading edge had a greater effect on the measured pressure distributions. The pressure coefficients are compared against the results for the roof with no panels attached. The model results with no panels attached agreed well with full-scale results from the Texas Tech test building.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.733-742
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• 2020

Taking the cylindrical float of the floating fence of a floating litter collection device as the research object, based on the shallow immersion characteristics of the cylindrical float, the Morison equation is modified, and the interaction between regular waves and the partially immersed horizontal cylindrical float is discussed in combination with scale model test. The results show that the modified Morison equation can accurately predict the wave force of the horizontal cylindrical float and reveal the influence of amplitude, immersion depth and period on the wave force of the cylindrical float. For partially immersed cylindrical floats, the wave force increases with the increase in wave height and decays with the increase in period. The positive value distribution of the wave force is larger than that of the negative direction, and the difference between the positive and negative directions is mainly affected by the immersion depth.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1109-1118
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• 2021

The construction of STELLA-2 facility is on-going to demonstrate the safety system of PGSFR and to provide comprehensive understanding of transient behavior under DBEs. Considering that most events are single-phase natural circulation flow with slow transient, STELLA-2 was designed with reduced-height of 1/5 length scale. The ratio of volume to surface area in the vessel can relatively increase resulting in excessive heat transfer. Therefore, a steady-state thermal-hydraulic analysis was performed and the effect of design change to reduce the heat transfer through redan was investigated. The heat transfer through single wall redan in STELLA-2 was 3% of the core power, comparable to 1% of the core power in PGSFR. By applying the insulated redan, about 70% of decrease effect was observed. The effect on transient behavior was also evaluated. The conclusion of this study was directly applied to the STELLA-2 design and the modified version is under construction.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.165-172
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• 1995

Twenty six subject drove screws with a screw driver into thick wooden sheet at three vertical and horizontal locations. Subjects drive screws for 3 minutes at each location and they assessed the conditon using the psychophysical scale. An ANOVA showed that only vertical location was a signicant factor in determining the pain ratings of various body parts. Driving screws at elbow height on the vertical surface ans with the lower arm close to the body on the horizontal surface were the work locations with the smallest ratings of perceived pain and discomfort. Wearing gloves had significant effects on reducing the pain of the hand.

• Journal of the Korean Statistical Society
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• v.23 no.1
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• pp.187-198
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• 1994

We derive a new Cramer-Rao type lower bound for the reciprocal of the density height of the median-unbiased estimators which improves most of the previous lower bounds and is attainable under much weaker conditions. We also identify useful necessary and sufficient condition for the attainability of the lower bound which is considerably weaker than those for the mean-unbiased estimators. It is shown that these lower bounds are attained not only for the family of continuous distributions with monotone likelihood ratio (MLR) property but also for the location and scale families with strong unimodal property.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.581-582
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• 2009

Continuous deep girders which transmit the gravity load from the upper wall to lower columns have frequently long end shear spans between the boundary of the upper wall and the face of the lower column. This paper presents the results of tests and analyses performed on three 1:2.5 scale specimens with long end shear spans, (the ratios of shear-span/height : 2.0

• Journal of The Korean Astronomical Society
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• v.8 no.1
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• pp.35-39
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• 1975

Effect of the ratio of mixing length to the pressure scale-height ${\alpha}$=l/HP on the effective temperature has been investigated under some simplifying assumptions. The result is compared with that of the existing model calculations. The role of convection zone in the stellar evolution is briefly summarized.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.76.2-76.2
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• 2010

We report the extended far-ultraviolet (FUV) halo of NGC 891 above the galactic plane. The FUV intensity distribution is well described by two exponential components, one with the scale height of ~0.34 kpc and the other of ~2.3 kpc. The extraplanar FUV halo is traceable up to > 5 kpc. The FUV halo is attributable to scattered-off starlight by extraplanar dust. Using Monte-Carlo radiative transfer simulations, the FUV intensity distribution along the minor axis is found to be well modeled with two dust comonents. Its implications are discussed.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.22-23
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• 2003

The new method of x-ray photon correlation spectroscopy (XPCS) [1] is developed recently for probing the dynamics of surface height fluctuations as a function of lateral length scale. Measurements were performed on supported polystyrene (PS) films of thicknesses varying from 84 to 333 nm at temperatures above the PS glass transition temperature. Within a range of wave vectors spanning $10^{-3}$ to $10^{-2}$ $nm^{-1}$, good agreement is found between the measured surface dynamics and the theory of overdamped thermal capillary waves on thin films. Quantitatively, the data can be accounted for using the viscosity of bulk PS. (omitted)

• Magazine of the Korean Society of Agricultural Engineers
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• v.6 no.2
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• pp.816-825
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• 1964

1. Outline: The flow of the siphon spillway is very intricate and affected by vacuous condition. It is an intresting problem to make vacuum rapidly in_siphon, i.e, to provoke the perfect siphonaoge with the lowest water-level of overflow. The hydraulic experiments of siphon spillway have practiced at the Masan Lake, Haenam, the province of Junnam and gained rational and economical results which cannot be odtained by calculation. 2. Experiment: The model scale was a half of that of the prototype. 3. Results and discussion: In the experiments of 14 runs, washing, overflow water level, outlet, water level of cushion, phenomenon of water flying and water pressure of every part, etc. were studied. a) The relation of overflow water-level at siphon inlet and deflector When the elevation of the deflector is 10. 65m and the form of deflector O.4m long is the hypotenuse of an $45^{\circ}$ isosceles triangle, the over flow water-level is the minimum, i. e. the siphonage was excellent. There is no effect by the rising of overflow water-Ievel between 11.95m to 1O.65m of deflector elevation (in the first plan, it is 11.05m). But the overflow water-level rises remarkably in the outside region of the above limits. b) The relation of overflow water-level, the length of cushion and standard height of the base. The reduction of the length of cushion brings the rising of overflow waterlevel, and the rising of the standard height of the base brings the rising of overflow water level. For the long cushion length and low standard height of the base, it cannot be expeted to have the falling of overflow water-level. The most satisfactory data were obtained at 5.20m of the base standard height and 6.1m of the length of cushion. The first vah,le planned was 5.70 m and 4.30m.