• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.229-239
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• 1998

This study investigated ecological and growth characteristics of Sorbus alnifolia for usage of landscape woody plant. The results are obtained as follows: 1) The results of investigate the native Sorbus alnifolia vegetations in Seoul and Kyonggi-do are as follows. From the investigation of canopy and understory, Pinus densiflora, Pinus rigida, Quercus mongolica Quercus dentata and Quercus aliena grow well in natural habitat of Sorbus alnifolia. While Rhod. mucronulatum, Symplocos chinensis, Corylus hetrophylla and alnifolia. While Rhod. mucronulatum, Symplocos chinensis, Corylus hetrophylla and Lindera obtusiloba are commonly found from shrub structure in the habitat. These structure pattern of natural setting would be applied for ecological planting design. 2) The Mt. Rabong area, which locates near a heavy factory district and is considered as environmental dteriorated area has the lowest soil acidity range among three investigated area. Sorbus alnifolia grows in where contains low soil acidity and inorganic nutrient. It might concluded that Sorbus alnifolia be tolerates to air pollution. 3) From the investigation of good specimen tres, the oldest good specimen trees of Sorbus alnifolia have grown in Seoul and Kyonggi-Do for 130 years with 15m height and 12m width. Most of good specimen trees are over 50 years old with 10~15m height, 4.5-12m width. These growth shape and form could be recommend that Sorbus alnifolia would be used as street tree and landscape woody plant in urban park.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.10-17
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• 2017

This paper deals with a comparison of performance between tip rake propeller and normal propeller in P.O.W condition. In comparison with normal propeller, tip rake propeller is good at preventing occurring negative effect: tip vortex, etc. But, officially formulated information about tip rake propeller doesn't become known. So this paper makes design variables about rake factors and applies them to propeller geometry. And propellers applied design variables are compared with each other about open water propeller efficiency. Also this paper confirms a vorticity reduction at propeller tip.

• Tribology and Lubricants
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• v.30 no.4
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• pp.199-204
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• 2014

Various heat-treated and surface coating methods are used to mitigate abrasion in sliding machine parts. The most cost effective of these methods involves hard coatings such as diamond-like carbon (DLC). DLC has various advantages, including a high level of hardness, low coefficient of friction, and low wear rate. In practice, a supporting layer is generally inserted between the DLC layer and the steel substrate to improve the load carrying capacity. In this study, an indentation and sliding contact problem involving a small, hard, spherical particle and a DLC-coated steel surface is modeled and analyzed using a nonlinear finite element code, MARC, to investigate the influence of the supporting layer thickness on the coating characteristics and the related coating failure mechanisms. The results show that the amount of plastic deformation and the maximum principal stress decrease with an increase in the supporting layer thickness. However, the probability of the high tensile stress within the coating layer causing a crack is greatly increased. Therefore, in the case of DLC coating with a supporting layer, fatigue wear can be another important cause of coating layer failure, together with the generally well-known abrasive wear.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.747-754
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• 2010

The objective of this study is improve the technology by various testing devices for measuring degree of compaction. The methods for quality control for compaction are very various. But, normally the specifications have provided PBT(Plate Bearing Test) method when inspector tested quality control. In spite of the PBT has a few weak points to reduce process and cost. In order to improve quality control method, analyzed in-situ test results between PBT and other devices.(LWDT and Geogauge).

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1250-1255
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• 2010

In this study, in order to examine the hydraulic characteristics for a crushed stone mat. it was accomplished discharge capacity test and soil-water characteristic curve(SWCC) with the object of the research. From the test result, it produced propriety mixed ratio of the crushed stone which mixes the sand. at the time of crushed stone 100% where it does not mixes the sand it appeared that permeability was biggest. increase of shock and content of the sand showed decrease of air entry value.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.215-220
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• 2014

Most of studies on wave height algorithms that are using at buoys describe algorithms using double integral to determine the position data from the acceleration data measured from the accelerometer. but sometimes, it can involve some cumulative error in that process, and result in misjudgment or unstabe system. On the other hand, It is widely known that the motion of fluid particles on or underneath a linear progressive wave is periodic and elliptic. This fact is considered in this article and leads a improved algorithms with no integral processing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.339-339
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• 2010

Photo-assisted wet chemical etching of GaN thin film was studied using KOH based solutions. A $2{\mu}m-2{\mu}m$ titanium line-and-space pattern was used as a etching mask. It is found that the etching characteristics of the GaN thin film is strongly dependent on the pattern direction by unisotropic property of KOH based solution. When the pattern was aligned to the [$11\bar{2}0$] directions, ($10\bar{1}n$)-facet is revealed constructing V-shaped sidewalls.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.420-423
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• 1997

The oxygen saturation of blood can be measured by sensing the difference absorption in optical spectra of Hb and $HbO_2$, as the well known previous study. [1] In this study we developed the noninvasive tissue reflectance oximeter(TRO) using three kinds of LEDs which produce a peak spectral emission at a wavelength of 565, 660 and 940nm. And we tested the unction of the TR oximeter by comparing the output signals measured on normal tissue to measured on low oxygenated tissue. The results showed that oxygen saturation of blood and biological tissue can be monitored from the separation arrangement light source and detector.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4
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• pp.217-223
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• 2005

In this paper, we propose a predictive block constrained trellis coded quantization (BC-TCQ) to quantize cepstral coefficients for the distributed speech recognition. For Prediction of the cepstral coefficients. the 1st order auto-regressive (AR) predictor is used. To quantize the prediction error signal effectively. we use a BC-TCQ. The performance is compared to the split vector quantizers used in the ETSI standard, demonstrating reduction in the cepstral distance and computational complexity.

• Journal of the Korean Society for information Management
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• v.13 no.1
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• pp.47-63
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• 1996

Conventional automatic indexing methods for Hangul texts can be classified into two groups as follows: One is to extract index terms by removing non-indexable segments from word-phrases, and the other is to generate index terms from the morphemes of word-phrases. The former suffers from the problem of word boundaries when documents contain many compound nouns. The latter can overcome the word boundary problem by extracting simple nouns, but has many overheads to develop a lot of linguistic knowledges needed in the indexing procedure. In this paper we propose a new indexing method based on n-grams. This method alleviates the problems of previous indexing methods related with word boundaries and linguistic knowledges. We also compare the effectiveness of the n-gram based indexing method with that of the previous ones.