• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.2
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• pp.72-78
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• 2009

The demand for rainfall data in gridded digital formats has increased in recent years due to the close linkage between hydrological models and decision support systems using the geographic information system. One of the most widely used tools for digital rainfall mapping is the PRISM (parameter-elevation regressions on independent slopes model) which uses point data (rain gauge stations), a digital elevation model (DEM), and other spatial datasets to generate repeatable estimates of monthly and annual precipitation. In the PRISM, rain gauge stations are assigned with weights that account for other climatically important factors besides elevation, and aspects and the topographic exposure are simulated by dividing the terrain into topographic facets. The size of facet or grid cell resolution is determined by the density of rain gauge stations and a $5{\times}5km$ grid cell is considered as the lowest limit under the situation in Korea. The PRISM algorithms using a 270m DEM for South Korea were implemented in a script language environment (Python) and relevant weights for each 270m grid cell were derived from the monthly data from 432 official rain gauge stations. Weighted monthly precipitation data from at least 5 nearby stations for each grid cell were regressed to the elevation and the selected linear regression equations with the 270m DEM were used to generate a digital precipitation map of South Korea at 270m resolution. Among 1.25 million grid cells, precipitation estimates at 166 cells, where the measurements were made by the Korea Water Corporation rain gauge network, were extracted and the monthly estimation errors were evaluated. An average of 10% reduction in the root mean square error (RMSE) was found for any months with more than 100mm monthly precipitation compared to the RMSE associated with the original 5km PRISM estimates. This modified PRISM may be used for rainfall mapping in rainy season (May to September) at much higher spatial resolution than the original PRISM without losing the data accuracy.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1062-1065
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• 2004

We have analyzed the cause of black "mura" and measured it in prism light guide plate(LGP). Properties of components used in a backlight uint(BLU) have changed by simulation tool. We get major factor of black "mura" for improvement in prism LGP. For the improvement of black "mura", removal of brightness "mura" at input light part must precede preferentially because of reflection characteristic of the prism LGP. Removal of brightness "mura" is improved by hanging of input light part in LGP and dispersion treatment.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1233-1235
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• 2004

We have designed High Performance Prism LGP in 17 inch TFT-LCD. In test result to embody high brightness BLU in case of LGP of base and upper surface with 17 inch, thickness 8mm adding prism construct, it is superior brightness improvement than previous that of printing form about some 20% and in this course to embody actual material it succeeded prism LGP production by 17 inch injection form process.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.15-18
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• 2009

Photopia, LightTools, and ASAP are typical software for optical design of a luminaire. Through using various lighting simulation software some different results can be found under the same conditions. Therefore, the purpose of this paper is to compare simulated photometric data and values illuminance of different types of LED prism luminaires under the same conditions. Then, LED prism luminaires were divided into the linear type and the planar type. Also three kinds of prism angles were divided into $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$. In addition, the reasons for such differences were analyzed.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.8
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• pp.915-922
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• 2005

This experimental study is conducted to investigate effects of a splitter plate, which is set on the back side of a square prism in the uniform flow. The Reynolds number is $1.44{\times}10^{4}$ based on the width of the square prism. The measurement of velocity vector and pressure distribution are carried out 4 cases of length in the range of 0.5L to 2.0L with 0.5L interval and 3 cases of Position at 0L, 0.25L, 0.5L, Flow visualization is also executed by smoke-wire method to understand the mechanism of vortex formation The results show the strong vortex shedding patterns and drags are decreased effectively, when the position of splitter plate is 0L. And the drag reduction rate is in inverse proportion to the splitter plate length

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.384-387
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• 1995

Two axes lateral-shearing interferometer(LSI) specially devised for production line inspection lenses is presented. The interferometer composed with four prisms and a dove prism can test the lens performance including asymmetric aspheric lens. The dove prism which rotates the input image with respect to optical axis makes it possible. The wavefront passing through the test lens is reconstsucted by the phase derivative obtained form the two axes LSI system. Zernike-polynomials fitting of this wavefront is presented for determinating quantitative aberration of aspherical lenses.

• Archives of design research
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• v.19 no.3 s.65
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• pp.5-18
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• 2006

Digital information society shows a variety of contents of cross-categorial digital media in their inner or outer forms and concepts of the artistic aspects. In order to cope with such a complicated, unexpected trend in digital media and its industry, a new approach in the design process needs to be developed and adjusted with the new equipment of the creativity-thinking process of 'the Multi-Sensory Device (MSD),' 'the Multi-Dimensional Device (MDD),' and 'the Storytelling Device (SD)' in the Prism Effect-based Creativity-Thinking Process (PECTP). The PECTP is in principle designed to practically work with the four distinct techniques: 1) Physical Activity, 2) Linguistic Activity, 3) Visual Activity, and 4) Complex Activity. Consequently, this thesis notes that the nature of the cross-categorial design contents is necessarily non-directional since the creativity power inside the Prism Effect results in openness and diversity.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.71-75
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• 2006

In recent, various shapes of pattern in micron or nano scale are adapted in many applications due to their good mechanical or optical properties. Light guide panel (LGP) of the LCD is one of important applications for micro pattern and micro prism shape is one of the typical patterns. The size of the surface patterns in most applications is decreasing to the order of micron or even under micron. On the other hand, the area to be patterned keeps enlarging. These two trends in patterned products require tooling micro patterns on large surface, which has still many technical problems to be solved mainly due to pattern size and the tooling area. In this study, we fabricated prism shape of patterns using diamond cutting tool on some metal core and plastic core like PMMA. Some cutting conditions were investigated including cutting force, cutting depth and speed for different core materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.114-118
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• 2001

HP Laser Interferometer Measurement System[HP5529A] is one of the most powerful equipment for measurement of the motion accuracy. The straightness measurement system of the HP5529A is composed of wollastone prism and reflector. In this system, straightness error is measured by relative lateral motion between prism and reflector. But rotating motion of prism or reflector as moving optic causes not real straightness error but additive straightness error. Especially unwanted straightness error as this becomes very large when reflector is used as moving optic and an interval between reflector and prism is distant. In this paper, the compensation method is proposed for removing additive error and experiment is carried out for theoretical verification.

• Publications of The Korean Astronomical Society
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• v.8 no.1
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• pp.17-31
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• 1993

In order to check whether the 4-degree objective prism spectra can be used for deep spectroscopic studies of galactic structure, we measured the Rose(1984)'s seven indices between 3500 A and 4400 A for 19 Hyades stars on the Kiso Schmidt prism plate, K3496. By comparing the $4^{\circ}$-indices with those of Rose(1984), we have found that $H{\delta}/FeI$, $H{\gamma}/4325$, and P(3912)/P(CN) measured on the 4-degree prism spectra, are still useful for the derivation physical parameters.