• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3230-3232
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• 1999

In this paper describes the design and improvement of a hybrid module for dual slope A/D converter. Since the input voltage to be converted is very sensitive and small. A/D converter must have the temperature stability. low-drift, and the high-resolution the conversion. A dual slop A/D converter circuit which is controlled by microprocessoer has been developed to reduce the offset voltage and the drift characteristics of operation amplifiers, and to improve the A/D conversion speed. Also hybrid module has been adapted to obtain the to obtain the stable and accurate A/D conversion for low cost use. The evaluation of the designed hybrid module has been shown as having a good performance, which will give usefull application to the industrial measurements use.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.80-93
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• 2000

This study measured the shearing resistance of the roots of the Pinus Koraiensis by the tensile strength gained through their individual tensile test for the Root Reinforcement Model. On the basis of the shearing resistance value calculated through such a process the factor of safety(Fs) was comparatively presented by using the simplified Janbu Method in PCSTABL5M, the slop-analyzing software which had been developed in Purdue University of the U.S.A according to the shape of a slope and the type of soil. The results to have measured a stress and the factor of safety(Fs) by experiment are as follows. 1) The mean root diameter of the Pinus Koraiensis used for this experiment was 2.483mm and the mean tensile stress was calculated as 422.846(kgf/$\textrm{cm}^2$). In the strain ratio of material and the elastic modulus was measured 7.8%, 9,291.92(kgf/$\textrm{cm}^2$). 2) The shearing strength including the resistance of soil and root is expressed as Rt=C+Cr+$\sigma$.tan . ΔCr(kg/$\textrm{cm}^2$) of the shearing resistance calculated by estimating the areal ratio of roots at 10 is 0.253(kgf/$\textrm{cm}^2$). 3) As the result of making an analysis of the natural slope stability by the soil parameter, the factor of safety(Fs) was calculated at 1.795 in CL, and the stability analysis of the root reinforcement slope, Fs was calculated at 1.952. However, since a precise analysis of the controlled factors of the slope analyses are demanded for more accurate dynamic analyses, the future demands a study on this.

• Journal of the Korean Geosynthetics Society
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• v.3 no.2
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• pp.13-21
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• 2004

This paper deal with the analysis of the causes about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extraction from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy, which are causes of the collapse.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.2
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• pp.74-83
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• 2001

The purpose of this study was investigate to the influence of forest roads characteristics and environment factors on the soil erosion, stability and vegetation survival of cut slope in forest roads. The results obtained could be summarized as follows; 1. The correlated factors between slope erosion and variables in cut slope were altitude, convex, degree of slope, length of slope and soil depth. In the stepwise regression analysis, length of slope and soil hardness was a high significant and its regression equation was given by -89.6136 + 15.0667X14 + 16.6713X15($R^2$ = 0.6712). 2. The main factors influencing the stability of cut slope were significant in order of coverage, middle, convex, length of slope and north, and its discriminant equation was given by -1.019 + 0.064X22 - 0.808X8 - 0.622X24 + 0.742X11 - 0.172X14 - 0.545X6 ($R^2$ = 0.793). 3. The centroids value of discriminant function in the stability and unstability estimated to 1.244 and -1.348, respectively. The boundary value between two groups related to slope stability was -0.1038. The prediction rate of discriminant function for stability evaluation of was as high as 91.3%. 4. The dominant species of invasion vegetation on the cut slope consist with Carex humilis, Agropyron tsukushiense var. transiens, Calamagrostis arundinacea, Miscanthus sinensis var. purpurascens, and Ixeris dentata in survey area. The rate of vegetation invasion more increased by time passed. 5. The life form of invasion vegetation in cut slop showed to $H-D_1-R_{2,3}-e$ type of the hemicryptophyte of dormancy form, dissem inated widely by wind and water of dissminule type, moderate extent and narrowest extent of radicoid type, erect form of growth form. 6. The correlated factors between forest enviroment and coverage appeared north, passage years and middle position of slope at 5% level. The forest environment factors influencing the invasion plants in survey area were shown in order to altitude, passage years, rock(none), forest type(mixed) and stone amount. The regression equation was given by 17.5228 - 0.0911X3 + 3.6189X28 15.8493X22 19.8544X25 + 0.3558X26 ($R^2$ = 0.4026).

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.302.1-302.1
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• 2016

Solution-processed amorphous metal-oxide thin-film transistors (TFTs) are considered as promising candidates for the upcoming transparent and flexible electronics due to their transparent property, good performance uniformity and possibility to fabricate at a low-temperature. In addition, solution processing metal oxide TFTs may allow non-vacuum fabrication of flexible electronic which can be more utilizable for easy and low-cost fabrication. Recently, for high-mobility oxide TFTs, multi-layered oxide channel devices have been introduced such as superlattice channel structure and heterojunction structure. However, only a few studies have been mentioned on the bias illumination stress in the multi- layered oxide TFTs. Therefore, in this research, we investigated the effects of bias illumination stress in solution-processed bilayer oxide TFTs which are fabricated by the deep ultraviolet photochemical activation process. For studying the electrical and stability characteristics, we implemented positive bias stress (PBS) and negative bias illumination stress (NBIS). Also, we studied the electrical properties such as field-effect mobility, threshold voltage ($V_T$) and subthreshold slop (SS) to understand effects of the bilayer channel structure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1551-1556
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• 2016

A combined CPG (Central Pattern Generator) based foot trajectory and GP (Genetic Programming) based joint compensation method is presented for the adaptive humanoid walking. The CPG based foot trajectory methods have been successfully applied to basic slops and variable slops with slow rates, but have a limitation for the steep slop terrains. In order to increase an adaptability of humanoid walking for the rough terrains, a GP based joint compensation method is proposed and combined to the CPG (Central Pattern Generator) based foot trajectory method. The experiments using humanoid robot Nao are conducted in an ODE based Webots simulation environmemt to verify a stability of walking for the various aslope terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performances especially for the steep varied slopes.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.39-49
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• 1999

Urban streams have, recently, been straightened and widened to alleviate flooding problem. As a result, the stream have been modified inadvertently for ecological functions and microtopography. In this study, we investigated riparian vegetation and microtopography of the tributaries of Han River before and after the monsoon rain in summer. The purpose of this study was to relate the stream microtopography to the distribution of riparian vegetation. The stream microtopography was investigated for its scale and pattern. Vegetation was investigated from 131 plots by Braun-Blanquet method. The distribution of riparian vegetation was significantly correlated with the stream microtopography. Various herbaceous species occurred at stream bank slop, high terrace and channel side. However, at channel side and concave part of terrace where soils were in high moisture level, only a few wetland species were dominated. The complexity of the microtopography in the stream corridors led to heterogeneous riparian vegetation. The vegetation showed more stability against flooding at the stream corridors with natural and complex microtopography than at the urban-type stream corridors with simple topographical features. The results showed that the development of riparian vegetation was influenced by the changes in microtopography, which was primarily determined by the shape and characteristics of channel. It seemed that a close-to-nature river system would be restored more readily with an understanding of microtopographical features affecting the distribution of riparian vegetation.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.653-660
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• 1999

The flow of non-rotation atmosphere with uniform stratification and wind past an isolated three dimensional topography obstacle is investigated with three-dimensional hydrostatic and non- hydrostatic numerical model. The characteristic of turbulence created the back of topography obstacle is usually defined by Froude number which is the function of upstream wind speed, the height of topography obstacle, and atmospheric stability. Turbulence tends to be formed more easily at the non-hydrostatic model than hydrostatic model. Especially, the difference between flow patterns of two models generated by isolated obstacle is more clear under low Froude number. The difference of flow patterns can be only seen at relatively low altitude, but at high altitude the patterns of two models are almost same. In this research, wind velocity in the parameters related with Froude number have great sensitivity at responsibility of numerical models. and slop of obstacle is also important factor at the flow pattern regardless of the species of numerical model

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.39-56
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• 1990

The purpose of this study is to analyze the roadside slope of mountainous Parkway. 48 sites were selected by Random Ranking Sampling. This study was researched on the slope condition with the cause of occurrence, the situation of fundamental engineering works and vegetation on slopes. The main results of this research are summarized as follow ; 1. Slope shapes are shown nine types in cut slope and four types in fill slope. 2. Generally, fill slopes are larger than cut slopes in slop area. 3. Grade is more steep than standard grade. 4. Main engineering works, which constructed for slope stability, are terracing, side-ditch wall, channel, concrete trellis works and wire fence. 5. Roundabout channel were many constructed within the sector of Ukmojeong-Deokdong, but were few constructed within the sector of Banseon-Seongsam pass and Cheoneun Temple-Seongsam pass. 6. Most. of side-ditch wall were constructed of concrete and wet-masonry. 7. In vegetation works, many exterior species were selected. 8. Planting pattern was not combinated with the national park landscape.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.3
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• pp.83-97
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• 2009

The objects of study is to propose criteria for physical river disturbance assessment and as case study to show the application results for river improvement. For this purpose, the river disturbance assessment method for past disturbance process and the present-day potential natural state of stream is proposed. To assess the disturbance of the Youngcheon River caused by river improvement, One ares of Nam River was selected for the reference reach and two areas of Youngcheon River were selected for the comparison reach. And these reaches were surveyed and analyzed according to applying criteria of the river disturbances assessment. The assessment indices were physical factors as like epifaunal (bottom), embededness, velocity/depth regime, sediment deposition, channel flow status, channel alteration, frequency of riffles, bank stability, vegetative protection and riparian zone etc. The results showed that physical river environment in Youngcheon River area was disturbed by artificial revetment and bed excavation, consequently this disturbance give rise to impact of ecosystem in river. Hereafter, the criteria for river disturbance assessment are needed to consider various river characters as bed materials and bed slop etc.