• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.19-27
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• 2014

Exterior vertical illuminance is an important factor for lighting control. But, there are not many researches about the exterior illuminance on a vertical surface. In this study, we predicted the exterior illuminance on a vertical surface using vertical luminous efficacy. First, we calculated the vertical luminous efficacy according to the sky clearness category. And we performed the statistical analysis of the measured and the calculated illuminance with luminous efficacy. The MBE and RMSE of the predicted exterior illuminance were-1.2% and 15.5%, respectively. Second, the annual illuminance on a vertical surface calculated with the luminous efficacy and the short-term measured solar irradiance was suggested in this study.

• Journal of the Korean GEO-environmental Society
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• v.17 no.7
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• pp.27-33
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• 2016

This study expanded Terzaghi arching formula, which assumed a vertical surface as a sliding surface, to consider an arbitrarily inclined surface as a sliding surface and examined the effect of a sliding surface. This study firstly developed a formula to expand the existing Terzaghi arching formula to consider an inclined surface as well as a vertical surface as a sliding surface under the downward movement of a trap door. Using the expanded formula, the effect of excavation, ground, and surcharge conditions on a vertical stress was examined and the results were compared with them from Terzaghi arching formula. The comparison indicated that the induced vertical stress was highly affected by the angle of an inclined sliding surface and the degree of influence depended on the excavation, ground, and surcharge conditions. It is expected that the results from this study would provide a better understanding of various arching phenomenon in the future.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.49-56
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• 2015

To investigate fiber orientation of Korean traditional paper, Hanji, the fiber arrangements on the surface and cross section of Hanji were observed by scanning electron microscope (SEM). The surface observation showed that the fibers of traditional paper were arranged in vertical and horizontal directions, and those of ssangbal sheet forming were arranged more in vertical direction. The fibers of machine made Hanji and copying paper were usually arranged in vertical direction. As for the observation of cross section of traditional paper, fibers arranged in horizontal direction tended to be increased with the increase of thicknesses. The thick traditional paper have cracks in the middle part of structural section of paper. They were larger in cross section in horizontal direction than in vertical direction. The horizontal arrangement of traditional paper seemed to be about 8% to 14% higher to the vertical arrangement, which is very lower to other papers.

• Geomechanics and Engineering
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• v.19 no.3
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• pp.201-215
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• 2019

A new approach of analyzing the displacements and stress of the surrounding rock for shallow tunnels excavated under non-axisymmetric displacement boundary conditions on a vertical surface is investigated in this study. In the proposed approach, by using a virtual image technique, the shear stress of the vertical ground surface is revised to be zero, and elastic solutions of the surrounding rock are obtained before stress revision. To revise the vertical normal stress and shear stress of horizontal ground surface generated by the combined action of the actual and image sinks, the harmonic functions and corresponding stress function solutions were adopted. Based on the Boussinesq's solutions and integral method, the horizontal normal stress of the vertical ground surface is revised to be zero. Based on the linear superposition principle, the final solution of the displacements and stress were proposed by superimposing the solutions obtained by the virtual image technique and the stress revision on the horizontal and vertical ground surfaces. Furthermore, the ground settlements and lateral displacements of the horizontal and vertical ground surfaces are derived by the proposed approach. The proposed approach was well verified by comparing with the numerical method. The discussion based on the proposed approach in the manuscript shows that smaller horizontal ground settlements will be induced by lower tunnel buried depths and smaller limb distances. The proposed approach for the displacement and stress of the surrounding rocks can provide some practical information about the surrounding rock stability analysis of shallow tunnels excavated under non-axisymmetric displacement boundary conditions on a vertical surface.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.417-422
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• 2001

The vertical structure of atmosphere was observed In investigate the variation of surface ozone concentration by vertical downward mixing of residual ozone in the atmospheric boundary layer at the Busan coastal area. Airsonde and pilot balloon measurements were made at Gamcheondong and the Kimhae airport for April 26~27, 1996. The vertical potential of potential temperature showed a residual layer between 510m and 1800m from 2100LST April 26 to 0900LST April 27. The downward mixing of ozone in the residual layer of the atmospheric boundary layer was confirmed from vertical profile of mixing ratio near 600m in the morning. The thickness of the sea breeze layer was 900m at 1500LST April 26. Thereafter, it become to be lowered with time A low level jet was measured near 900m at 0300LST on April 27 from a pibal measurement. Early morning sharp increase of surface ozone concentration at the Busan coastal area was caused by vertical downward mixing of ozone concentration rather than by photochemical reaction In the atmospheric boundary layer.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.63-68
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• 2008

This paper describes about the simulation and the experimental results of optical cavity with curved mirror surface and vertical mirror surface to improve the light intensity and efficiency of the optical sensors. When we use the vertical mirror surface, the distribution of light reached to the filter surface of detector shows an elliptical shape. Whereas, the curved mirror surface focuses the light into circular shape. Therefore, due to focusing effects in case of using curved mirror surface, the light intensity per unit area has been improved. Consequently, the output voltage of gas sensor has been expected to increase. Based upon the simulation, the experiment of gas sensor has been conducted with $CO_2$ gas from 0ppm to 2,500 ppm at 250 ppm step and $25^{\circ}C$, 45%R.H. ambient. The output voltage of gas sensor that has a curved mirror surface increases approximately 200 mV than that of vertical mirror surface.

• Fashion & Textile Research Journal
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• v.22 no.2
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• pp.222-232
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• 2020

This study analyzes changes in the knees, hips, and hip joint length according to the different angles of bending knees by 45°, 90°, and 135° respectively for knees, hips, and the hip joint that have high fracture rates when falling down. The research subjects were 10 elderly women in their 60s (or older) that obtain data collected through direct measurement. For analysis, the study drew a diagram of elongation and shrinkage based on changes and change rate from a straight posture (0°) and conducted a statistical analysis on differences of body surface length by zone according to movements. The more the knees were bent, the vertical surface length in front of the knees, the horizontal surface length above the knee line, the horizontal body surface length below the knee lines on the back, and the vertical surface lengths between front side lines and the side lines increased; however, the vertical surface length on the back decreased. For the hip joint, the difference in the vertical surface length was more distinctive when compared to the horizontal. Finally, the horizontal surface length increased below the hips and the vertical surface length increased in most areas except the sidelines and the front. The result of the change in body surface length according to the movements of this study can be utilized in the development of the motion-variable protector.

• Explosives and Blasting
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• v.15 no.4
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• pp.11-17
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• 1997

Impulsive vibration velocity is monitored at the surface and the boundary surface of rocks as various impulsive forces of horizontal and vertical directions were given to rocks which had difference in uniaxial compressive strength for investigate to the vibration velocity of rocks according to the impulsive direction and the monitoring site. The vibration velocity of the boundary surface of rocks was about 2.9 times or much larger than that of the surface at the same scaled distance in the case of horizontal impulsive forces, and was above 4.2 times in the case of vertical impulsive forces. The attenuation exponents of the vibration velocity equations in the surface and the boundary surface of rocks make a vast difference with the impulsive directions, but is makes little difference in the case of the same impulsive direction. The ratio of vibration constants of the surface to the boundary surface of rocks is that square and cube root scaled equation is a range of 2.7∼3.0 and 4.9∼5.0 respectively in the case of horizontal impulsive forces, and is a range of 4.2∼5.7 and 7.7∼11.5 respectively in the case of vertical impulsive forces.

• Journal of Korean Society on Water Environment
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• v.39 no.3
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• pp.215-222
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• 2023

Zooplankton are primary consumers in the food web connecting primary producers and predators such as small fish, playing an important role in energy transfer in aquatic ecosystems. Therefore, it is essential to understand the zooplankton community structure in material cycle and energy flow in aquatic ecosystems. Zooplankton in large rivers with a low flow rate would distribute vertically as in lakes. In this study, we collected zooplankton by surface water filtration and vertical haul method with 64 ㎛-mesh plankton net at three stations (ND-1, ND-2, ND-3) in Nakdong River fortnightly from June 2018 to December 2019. Species composition and individual densities were analyzed. All three stations showed differences in relative abundance of zooplankton groups between surface water and vertical integrated water, with the largest difference shown in the deepest station, ND-2. In vertically integrated water at ND-2, the relative abundance of rotifera was low by a maximum of 25% and that of cladocera was high by a maximum of 22% compared to surface water samples. These results indicate that surface water filtration method is not enough to represent the community structure of zooplankton compared to the vertical haul method in large rivers.

• International Journal of Internet, Broadcasting and Communication
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• v.4 no.2
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• pp.22-27
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• 2012

The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).