• Title/Summary/Keyword: Antecedent condition

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Influence of Antecedent Rainfall in Stability Analysis of Unsaturated Soil Slope (불포화토 사면 안정해석에서 선행강우의 영향에 관한 연구)

  • Lee, Yeongsaeng;Yoon, Seunghyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1073-1082
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    • 2015
  • The behavior of the unsaturated soil slope can be influenced by the various factors such as the hydraulic characteristics, the mechanical characteristics, the coefficient of conductivity, the stratifications, the rainfall conditions i.e. the rainfall intensity, the rainfall pattern, the duration time of the rainfall and the antecedent rainfall etc. It is known that the slope failure is influenced greatly by the antecedent rainfall rather than the rainfall condition at the failure time, so the antecedent rainfall is supposed to be a very important factor in slope stability analysis among these factors. To predict and to prevent the slope failure by the rainfall, the distribution of the matric suction by the antecedent rainfall must be considered first of all and the slope stability analysis should be carried out by considering the successive rainfall characteristics. In this research, 3 samples with different quantity (5%, 10%, 20%) of silts were prepared and the SWCC (Soil-water characteristic curve) tests were carried out and the associated parameters were analyzed. After analyzing the distribution of the matric suction and the change of the mechanical characteristics such as the stress and the strength when applying the antecedent rainfall for one month and the successive intensive rainfall for 12 hours, the slope stability analyses were carried out numerically. And the influence of the antecedent rainfall for one month and the SWCC on the stability of a slope were compared and analyzed.

The Effects of Gender Cue and Antecedent Case on the Immediacy of Pronominal Resolution (대명사의 성별단서와 선행어 격이 참조해결의 즉각성에 미치는 효과)

  • JaehoLee
    • Korean Journal of Cognitive Science
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    • v.4 no.1
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    • pp.51-86
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    • 1993
  • The purpose of this study was to investigate on-line comprehension processing in pronoun resolution. The two important constraints investigated in this study were the gender cue of pronoun and the antecedent case. Using antecedent probe recognition task. Experiment 1 investigated the effects of gender cues and antecedent cases on probe recognition time. There were on signigicant effects of employed variable. This result suggest the possibilty of immediate antecedent assignment depending on the degree of syntactic constraints satisfaction. In Experiment 2. using antecedent probe recognition task. the primed activation level differences between antecedents and non-antecedents over time-course intervals from 0 to 250msec were measured. The effect of gender cues was obtained over 0-250msec time-course condition. This indicates that the gender cues can determine the assignment of proper antecedent for a pronoun. In Experiment 3, subect-case pronouns were used only:Unambiguous gender cues were given and the time-course intervals of 250 and 750msec were employed. A signigicant interaction effect of antecedent cases with probe conditions was obtained. All the results of this research suggest that gender cues are powerful constraints for pronoun resolution.

Parameter Estimation of VfloTM Distributed Rainfall-Runoff Model by Areal Rainfall Calculation Methods - For Dongchon Watershed of Geumho River - (유역 공간 강우 산정방법에 따른 VfloTM 분포형 강우-유출 모형의 매개변수 평가 - 금호강 동촌 유역을 대상으로 -)

  • Kim, Si Soo;Jung, Chung Gil;Park, Jong Yoon;Jung, Sung Won;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.1
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    • pp.9-15
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    • 2013
  • This study is to evaluate the parameter behavior of VfloTM distributed rainfall-runoff model by applying 3 kinds of rainfall interpolation methods viz. Inverse Distance Weighting (IDW), Kriging (KRI), and Thiessen network (THI). For the 1,544 $km^2$ Dongcheon watershed of Nakdong river, the model was calibrated using 4 storm events in 2007 and 2009, and validated using 2 storm events in 2010. The model was calibrated with Nash-Sutcliffe model efficiency of 0.97 for IDW, 0.94 for KRI, and 0.95 for THI respectively. For the sensitive parameters, the saturated hydraulic conductivity ($K_{sat}$) for IDW, KRI, and THI were 0.33, 0.31, and 0.43 cm/hr, and the soil suction head at the wetting front (${\Psi}_f$) were 4.10, 3.96, and 5.19 cm $H_2O$ respectively. These parameters affected the infiltration process by the spatial distribution of antecedent moisture condition before a storm.

Cross-speaker anaphora in dynamic semantics

  • Yeom, Jae-Il
    • Language and Information
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    • v.14 no.2
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    • pp.103-129
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    • 2010
  • In this paper, I show that anaphora across speakers shows both dynamic and static sides. To capture them all formally, I will adopt semantics based on the assumption that variables range over individual concepts that connect epistemic alternatives. As information increases, a variable can take a different range of possible individual concepts. This is captured by the notion of virtual individual (= vi), a set of individual concepts which are indistinguishable in an information state. The use of a pronoun involves two information states, one for the antecedent, which is always part of the common ground, and the other for the pronoun. Information increase changes vis for variables in the common ground. A pronoun can be used felicitously if there is a unique virtual individual in the information state for the antecedent which does not split in two or more distinctive virtual individuals in the information state for the pronoun. The felicity condition for cross-speaker anaphora can be satisfied in declaratives involving modality, interrogatives and imperatives in a rather less demanding way, because in these cases the utterance does not necessarily require non-trivial personal information for proper use of a pronoun.

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Predicting Surface Runoff and Soil Erosion from an Unpaved Forest Road Using Rainfall Simulation (인공강우실험에 의한 임도노면의 지표유출량 및 토양유실량 평가)

  • Eu, Song;Li, Qiwen;Lee, Eun Jai;Im, Sangjun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.13-22
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    • 2015
  • Unpaved forest roads are common accessways in mountain areas being used for forestry purposes. The presence of forest roads produces large volumes of surface runoff and sediment yield due to changes in soil properties and hillslope profile. Rainfall simulation experiments were conducted to estimate the impacts of above-ground vegetation and antecedent soil water condition on hydrology and sediment processes. A total of 9 small plots($1m{\times}0.5m$) were installed to represent different road surface conditions: no-vegetation(3 plots), vegetated surface(3 plots), and cleared vegetation surface(3 plots). Experiments were carried out on dry, wet, and very wet soil moisture conditions for each plot. Above ground parts of vegetation on road surface influenced significantly on surface runoff. Runoff from no-vegetation roads(39.24L) was greater than that from vegetated(25.05L), while cleared-vegetation condition is similar to no-vegetation roads(39.72L). Runoff rate responded in a similar way to runoff volume. Soil erosion was also controlled by land cover, but the magnitude is little than that of surface runoff. Even though slight differences among antecedent soil moisture conditions were found on both runoff and soil erosion, runoff rate and soil losses were increased in very wet condition, followed by wet condition. The experiments suggest that vegetation cover on forest road surface seems most effective way to reduce surface runoff and soil erosion during storm periods.

Analysis of Regional Antecedent Wetness Conditions Using Remotely Sensed Soil Moisture and Point Scale Rainfall Data (위성토양수분과 지점강우량을 이용한 지역 선행습윤조건 분석)

  • Sunwoo, Wooyeon;Kim, Daeun;Hwang, Seokhwan;Choi, Minha
    • Korean Journal of Remote Sensing
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    • v.30 no.5
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    • pp.587-596
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    • 2014
  • Soil moisture is one of the most important interests in hydrological response and the interaction between the land surface and atmosphere. Estimation of Antecedent Wetness Conditions (AWC) which is soil moisture condition prior to a rainfall in the basin should be considered for rainfall-runoff prediction. In this study, Soil Wetness Index (SWI), Antecedent Precipitation Index ($API_5$), remotely sensed Soil Moisture ($SM_{rs}$), and 5 days ground Soil Moisture ($SM_{g5}$) were selected to estimate the AWC at four study area in the Korean Peninsula. The remotely sensed soil moisture data were taken from the AMSR-E soil moisture archive. The maximum potential retention ($S_{obs}$) was obtained from direct runoff and rainfall using Soil Conservation Service-Curve Number (SCS-CN) method by rainfall data of 2011 for each study area. Results showed the great correlations between the maximum potential retention and SWI with a mean correlation coefficient which is equal to -0.73. The results of time length representing the time scale of soil moisture showed a gap from region to region. It was due to the differences of soil types and the characteristics of study area. Since the remotely sensed soil moisture has been proved as reasonable hydrological variables to predict a wetness in the basin, it should be continuously monitored.

Relationship between Intestinal Metaplasia and Neutrophilic Infiltration of Stomach Caused by Helicobacter pylori Infection (위 Helicobacter pylori 감염 및 중성구침윤과 장상피화생의 연관성)

  • Park, Kang-Hoon
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.3
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    • pp.190-196
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    • 2005
  • Helicobacter pylori (H. pylori) infection is uncommon in developed countries, yet is common in underdeveloped and developing countries. Infection rate of H. pylori is minimally influenced by economic, environmental, and public health status and genetic factors. Korea is a developing country with a high incidence of H. pylori infection and gastric carcinoma, which is one of the leading causes of death. For this reason, accurate clinical and pathologic data on H. pylori-associated disease are very important. Intestinal metaplasia accompanies chronic gastritis and increases the risk of gastric carcinoma. For this reason, the relationship between H. pylori infection and intestinal metaplasia is very closely linked. Because of this, as the antecedent condition is guessed, it examines the relationship of the H. pylori and the intestinal metaplasia. Intestinal metaplasia is thought to be the basis in the development of intestinal type gastric carcinomas. Recent investigations showed that inflammatory reaction in the gastric fundus affect the development of gastric carcinogenesis. To verify neutrophilic activity in the gastric fundus and development of intestinal metaplasia in both gastric fundus and antral mucosa, their relationship was studied using 159 healthy patients who had undergone gastric endoscopic biopsies without any identifiable pathologic disesaes. When neutrophilic activity accompanied, incidence of intestinal metaplasia was significantly increased (p<0.05). H. pylori infection was statistically and significantly associated with the presence of intestinal metaplasia (p<0.05). These results suggest that H. pylori infection affected the development of intestinal metaplasia in the stomach. These results will help our understanding of H. pylori infection in the pathogenesis of intestinal metaplasia, a preneoplastic condition of the stomach. To reduce the incidence of gastric adenocarcinoma, eradication treatment of H. pylori is recommended when there's a neutrophilic activity in the gastric fundus.

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Absolute Stability of the Simple Fuzzy Logic Controller

  • Park, Byung-jae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.7
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    • pp.574-578
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    • 2001
  • The stability analysis for the fuzzy logic controller (FLC) has widely been reported. Furthermore many research in the FLC has been introduced to decrease the number of parameters representing the antecedent part of the fuzzy control rule. In this paper we briefly explain a single-input fuzzy logic controller (SFLC) or simple-structured FLC which uses only a single input variable. And then we analyze that it is absolutely stale based on the sector bounded condition. We also show the feasibility of the proposed stability analysis through a numerical example of a mass-damper-spring system.

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Derivation of Transfer Function Models in each Antecedent Precipitation Index for Real-time Streamflow Forecasting (실시간 유출예측을 위한 선행강우지수별 TF모형의 유도)

  • Nahm, Sun Woo;Park, Sang Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.1
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    • pp.115-122
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    • 1992
  • Stochastic rainfall-runoff process model which is mainly used in real-time streamflow forecasting is Transfer Function(TF) model that has a simple structure and can be easy to formulate state-space model. However, in order to forecast the streamflow accurately in real-time using the TF model, it is not only necessary to determine accurate structure of the model but also required to reduce forecasting error in early stage. In this study, after introducing 5-day Antecedent Precipitation Index (API5), which represents the initial soil moisture condition of the watershed, by using the threshold concept, the TF models in each API5 are identified by Box-Jenkins method and the results are compared with each other.

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Analysis of Unsaturated Flow Considering Hysteresis in Porous Media under Antecedent Rainfall (선행강우가 존재하는 다공성 매질에서 이력현상을 고려한 비포화 흐름 해석)

  • Park, Chang Kun;Sonu, Jung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.5
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    • pp.1137-1143
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    • 1994
  • Through the numerical analysis of the capillary pressure-based Richards equation with and without the effect of the capillary hysteresis under the boundary condition having an antecedent rainfall. the moving tendency of the wetting front, the redistribution of the moisture content, infiltration rate, cumulative infiltration etc, were computed. The effect of the capillary hysteresis cannot be neglected in analyzing an unsaturated flow, and the more accurate results may be obtained by the consideration of the hysteresis effect. If the effect of the hysteresis cannot be considered, the analysis by the use of the main wetting curve may give more reliable result than that of the main drying curve.

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