• 한국대기환경학회지
• /
• 제2권3호
• /
• pp.45-51
• /
• 1986

The simple and precise model for the estimation of rain acidity from the ambient air quality was developed using the theory of wet scrubber and the chemical equilibria of $SO_2, CO_2, and H_2O$ system. From the measured mixing height, and from the developed relationship between NTU (=number of transfer units) and the concentration of $SO_2$(aq) in rain drops, the HTU (= height equivalent to one transfer unit, i.e. mass transfer resistance) was estimated, and validated with the field-measured data. In Seoul, Korea where the effect of $SO_2$ on rainfall acidity is as high as 84% and the average mixing height is 1 km, the average HTU of $SO_2$ system was found to be 191.5m. The important parameters affecting HTU were identified as rainfall intensity and initial ambient concentration of $SO_2$, and their effects on the value of overall volumetric mass transfer coefficient were quantified.

• 한국생활과학회지
• /
• 제12권5호
• /
• pp.767-776
• /
• 2003

The purpose of this study was to classify side somatotypes of the trunk by analysing photographic data. Then their distribution according to the age groups was studied. The subjects were 315 females of 18 to 49 year-old. Thirty one photographic measurements were taken to each subject. The factors affecting the side somatotype of the trunk were obtained by principal component analysis, vertical size, posterior/anterior depth and neck posture. The side somatotypes of the trunk were classified into 4 types and their differences were shown by analysing photographic data. The side silhouettes of 4 types were compared with balanced type. By suggesting the canonical discriminant function with the unstandardized canonical coefficient, individual somatotype of the trunk could be discriminated from the photographic data of anterior neck height, anterior waist height, posterior waist depth, buttock height, and anterior depth at the level of back protrusion. The frequency distribution of the side somatotypes of the trunk according to the age groups could be applied for clothing construction and the rate of clothing production.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.606-609
• /
• 2006

Extraction of building is one of essential issues for the 3D city models generation. In recent years, high-resolution satellite imagery has become widely available, and this shows an opportunity for the urban mapping. In this paper, we have developed a semi-automatic algorithm to extract 3D buildings in urban settlements areas from high-spatial resolution panchromatic imagery. The proposed algorithm determines building height interactively by projecting shadow regions for a given building height onto image space and by adjusting the building height until the shadow region and actual shadow in the image match. Proposed algorithm is tested with IKONOS images over Deajeon city and the algorithm showed promising results.┌阀؀䭏佈䉌ᔀ鳪떭臬隑駭验耀

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
• /
• pp.287-292
• /
• 2001

The objective of this study is to verify the secondary flow and the total pressure loss distribution in the boundary layer fence installed linear turbine cascade passage and to propose an appropriate height of the boundary layer fence which shows the best loss reduction among the simulated fences. In this study three different boundary layer fence was installed which have different height. This study was performed by numerical method and the result showed the boundary layer fence which has the height of one third of the inlet boundary layer thickness showed the best loss reduction rate.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.91.2-91
• /
• 2001

This paper describes the path planning of an autonomous mobile robot using one camera-based sequence image processing. As an assumption, all objects in front of the mobile robot are located on the same plane where robot moves. Using the moving camera grounded on the autonomous mobile robot, the robot extracts the angular points of obstacle objects, calculates the height using the assumption and discrepancy between two consecutive images. In the image processing, angular points of objects must correspond so that they deliver the size of objects. Thus, the robot passes through if the object has not the height, like the paper or the shadow projected. Otherwise, the robot passes aside if ...

• 동력기계공학회지
• /
• 제5권2호
• /
• pp.30-35
• /
• 2001

A comparison of fully developed heat transfer and friction factor characteristics has been made in rectangular ducts with one wall roughened by five different shapes. The effects of rib shape geometries and Reynolds number are examined. The rib height-to-duct hydraulic diameter, pitch-to-height ratio, and aspect ratio of channel width to height are fixed at $e/D_e=0.0476$, P/e=8, and W/H=2.33, respectively. To understand the mechanisms of the heat transfer enhancements, the measurements of the friction factors are also conducted in the smooth and rough channels. The data indicate that the triangular type rib has a substantially higher efficiency index than any other ones in the range we studied.

• 한국생산제조학회지
• /
• 제21권5호
• /
• pp.708-713
• /
• 2012

The indented geometry for rockwell hardness indenter has been configured by using Confocal Laser Scanning Microscopy (CLSM). For this purpose, the CLSM can be well suited to construct the three-dimensional indented volume from the indented surface by rockwell hardness tester. Furthermore, the height data of HEI(height encoded image) by CLSM must be acquired at first and converted to indented surface later. And the indented surface patterns enable us to predict the indenter shape and volume. This volume can be used to study the rockwell hardness model as a volume parameter. As a result, the technique performed in this study by combining the CLSM with compensation technique is an excellent one to obtain the geometries of indented surfaces over a wide range of surface resolution in a micro scale. And it can be used for micro volume calculation.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
• /
• pp.539-545
• /
• 1997

Since the length of massive wall-structure is generally longer and larger than its thickness and a lift height of concrete of placement, cracks induced by hydration heat are governed by outer structural restriction rather than inner one. However, the degree of restriction control is expected to be affected by the sizes of wall thickness, length and a lift height. Thus, this analytical study aims at the development of relationship among those to minimize thermal cracks. In addition, the effect of types of cement on the thermal heats and stresses is evaluated for anti-sulphate and 2blended Portland cements concrete. It was found from analytical study that a lift height of concrete placement is the most important factor controlling thermal cracks, and the increase of lift heights is not always detrimental to structural safety.

• Journal of Mechanical Science and Technology
• /
• 제18권1호
• /
• pp.145-152
• /
• 2004

Effects of various baffle designs on acoustic characteristics in combustion chamber are numerically investigated by adopting linear acoustic analysis. A hub-blade configuration with five blades is selected as a candidate baffle and five variants of baffles with various specifications are designed depending on baffle height and hub position. As damping parameters, natural-frequency shift and damping factor are considered and the damping capacity of various baffle designs is evaluated. Increase in baffle height results in more damping capacity and the hub position affects appreciably the damping of the first radial resonant mode. Depending on baffle height, two close resonant modes could be overlapped and thereby the damping factor for one resonant mode is increased exceedingly. The present procedure based on acoustic analysis is expected to be a useful tool to predict acoustic field in combustion chamber and to design the passive control devices such as baffle and acoustic resonator.

• Journal of Mechanical Science and Technology
• /
• 제16권4호
• /
• pp.549-556
• /
• 2002

An investigation on the fully developed heat transfer and friction factor characteristics has been made in rectangular ducts with one-side roughened by five different shapes. The effects of rib shape geometries as well as Reynolds numbers are examined. The rib height-to-duct hydraulic diameter, pitch-to-height ratio, and aspect ratio of channel width to height are fixed at e/De=0.0476, P/e=8, and W/H=2.33, respectively. To understand the characteristics of heat transfer enhancements, the friction factors are also measured. The data indicates that the triangular type rib has a substantially higher heat transfer performance than any other ones.