• Title/Summary/Keyword: stability index

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The Assessment of Landslide Hazards in Gyeonggi Icheon area using GIS-based SINMAP Model Analysis (GIS기반의 SINMAP을 통한 경기도 이천지역의 산사태 위험도 분석)

  • Kwon, Ki-Bum;Lee, Hee-Chul;Chun, Jin-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.782-789
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    • 2010
  • Landslides cause enormous economic losses and casualties. Korea has mountainous regions and heavy slopes in most parts of the land and has consistently built new roads and large-scale housing complexes according to its industrial and urban growth. As a result, the damage from landslides becomes greater every year. In this study, performed a GIS-based landslide hazard analysis by SINMAP(Stability Index MAPping) model in Gyeonggi Icheon area coupling with geomorphological and geological data. SINMAP model has its theoretical basis in the infinite plane slope stability model with wetness obtained from a topographically based steady state model of hydrology. To Gyeonggi Icheon area landslides hazards evaluated, these SINMAP model were analysed results while simultaneously referring to the stability index map, where lines distinguish the zones categorized into the different stability classes and a table giving summary statistics.

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Stability of High Internal Phase Emulsions

  • Park, C.I.;Cho, W.G.
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.25 no.4 s.34
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    • pp.65-74
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    • 1999
  • We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5 wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of complex modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

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Voltage Stability Constrained Optimal Power Flow based on Successive Linear Programming (전압안정도를 고려한 연속선형계획법 기반 최적조류계산)

  • Bae, Seung-Chul;Shin, Yong-Son;Lee, Byong-Jun
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.220-223
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    • 2003
  • This paper presents VSCOPF(Votage Stability Constrained Optimal Power Flow) algorithm based on SLP(Successive Linear Programming) to interpret the large scale system. Voltage stability index used to this paper is L index to be presented by function form. The objective function consists of load shedding cost minimization. Voltage stability indicator constraint was incorporated in traditional OPF formulation. as well as the objective function and constraints are linearlized and the optimal problem is performed by SLP(Successive Linear Programming). In this paper, the effect of voltage stability limit constraint is showed in the optimal load curtailment problems. As a result, an optimal solution is calculated to minimize load shedding cost guaranteeing voltage security level. Numerical examples using IEEE 39-bus system is also presented to illustrate the capabilities of the proposed formulation.

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Stability of High Internal Phase Emulsions

  • Park, C-I.;W-G. Cho
    • Proceedings of the SCSK Conference
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    • 1999.10a
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    • pp.65-74
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    • 1999
  • We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of concentrated modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases :5; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence:. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

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Foreign Uncertainty and Housing Distribution Market in Korea

  • Jeon, Ji-Hong
    • Journal of Distribution Science
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    • v.16 no.12
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    • pp.5-11
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    • 2018
  • Purpose - We investigate the relationship between economic policy uncertainty (EPU) of the US and China and housing distribution economy in Korea using EPU indexes of two countries and the economic indicators in Korea. Research design, data, and methodology - We use the data such as the Korean housing price stability index (HPSI), housing purchase price index (HPPI), housing lease price index (HLPI), banking stock index (BSI), and consumer price index (CPI) with EPU indexes from January 1999 to December 2017. As an empirical methodology, we select the vector error correction model (VECM) due to the existence of cointegration. Result - As results of the impulse response function, the impact of the US EPU index has initially a negative response on the Korean HPSI, HPPI, and HLPI referring the housing distribution market including the economic variables, BSI, and CPI. Likewise, the impact of index in China has initially a negative response on economic indicators except the BSI in Korea. Conclusions - This study shows that the EPU index of the US has significantly negative relationships on all economic indicators in Korea. In this study, we reveal EPU of the US and China has dynamic impact on housing distribution economy returns in Korea.

CHARACTERIZATION OF STRICTLY OPERATOR SEMI-STABLE DISTRIBUTIONS

  • Choi, Gyeong-Suk
    • Journal of the Korean Mathematical Society
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    • v.38 no.1
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    • pp.101-123
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    • 2001
  • For a linear operator Q from R(sup)d into R(sup)d and 0$\alpha$ and parameter b on the other. characterization of strictly (Q,b)-semi-stable distributions among (Q,b)-semi-stable distributions is made. Existence of (Q,b)-semi-stable distributions which are not translation of strictly (Q,b)-semi-stable distribution is discussed.

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Study on Risk Assesment of Debris Flow using GIS (GIS를 이용한 토석류 위험성 평가에 관한 연구 (소규모 개발지역 중심으로))

  • Chang, In-Soo;Park, Eun-Young;Park, Ki-Bum;Kim, Sungwon
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.225-234
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    • 2013
  • The relationship between debris flow and topographical factors is essential for the reliable estimation of soil loss. The objective of this paper is to estimate stability index and soil loss for assessing landsliding risk caused by debris flow. SIMAP and RUSLE are used to estimate stability index and soil loss, respectively. The landsliding risk area estimated by using SIMAP is found to be different from the large land area estimated by RUSLE. It is found that the spatial distribution of soil cover significantly influences landsliding risk area. Results also indicate that stability index and soil loss, estimated by soil cover factor, improve the assessment of landsliding risk.

Cross-education Effects of Muscle Strength and Balance on Unilateral Isokinetic Exercise in Ankle

  • Son, Sung Min;Kang, Kyung Woo
    • The Journal of Korean Physical Therapy
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    • v.32 no.3
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    • pp.163-167
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    • 2020
  • Purpose: Unilateral strength training effects on contralateral sides have been demonstrated in previous studies for lower extremity exercise, upper extremity exercise, and unilateral surface electrical stimulation. This study was performed to investigate the effects of unilateral ankle training on muscle strength and the balance of contralateral lower extremity in healthy adults. Methods: Thirty healthy subjects were randomized equally to a training or a control group. Those in the training group received unilateral ankle isokinetic strengthening training of the dominant leg (right side) for 4 weeks. Contralateral single-limb balance, including Anterio-Posterior Stability Index (APSI), Medio-Lateral Stability Index (MLSI) and Overall Stability Index (OSI), was assessed before and after intervention. Results: Comparison of pre- and post-test data revealed significant improvements in ipsi- and contralateral ankle strengths, and significant improvement in contralateral single limb balance. Conclusion: These results have practical implications because they demonstrate that unilateral ankle isokinetic exercise improves ankle muscle strength and balance ability of contralateral lower extremity.

The Effects of the Capsule Density Uniformity on the Behavior of Cylindrical Capsules Transported through a Pipiline

  • Rhee, Kyoung-Hoon
    • Korean Journal of Hydrosciences
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    • v.5
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    • pp.115-124
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    • 1994
  • This paper presents the results of a study conducted to improve the understanding of the characteristics of cylindrical capsule flow in a pipeline by taking into account of the effect of capsule density uniformity. The effect fo capsule density variation in the axial direction was studied both experimentally and analytically. The experiments were conducted in a 190mm diameter straight pipe 17m long. The velocity, gap and tilt of capsules were measured under various conditions. In order to interpret the data on various capsule density conditions, the stability index given in the dimensionless number was introduced. The motion of capsules in pipelines is strongly affected by the stability of the capsules characterized by the statility index. The experiments conducted proved that the stability index is a vaild criterion for explaining and correlating data on the capsule motion and the capsule denisity uniformity.

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Effect of Isocyanate Index on the Properties of Rigid Polyurethane Foams Blown by HFC 365mfc

  • Kim, Sung-Hee;Kim, Byung-Kyu;Lim, Ho
    • Macromolecular Research
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    • v.16 no.5
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    • pp.467-472
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    • 2008
  • Rigid polyurethane foams (RPUFs) were fabricated from crude MDI (CMDI) and polypropylene glycols (PPGs) of various isocyanate indices with a physical blowing agent (HFC 365mfc). There was a tendency for the gel time to decrease and the tack-free time to increase with increasing index value. With increasing index value the foam density and compression strength decreased and the glass transition temperature, dimension stability and thermal insulation increased, while the cell size and closed cell content were virtually unchanged. Allophanate crosslinks and condensation reactions between the isocyanate groups, which are favored with a high index value, exerted significant effects on the properties of RPUFs.