• Title/Summary/Keyword: model factor

Search Result 11,946, Processing Time 0.062 seconds

Sensitivity Analysis of Climate Factors on Runoff and Soil Losses in Daecheong Reservoir Watershed using SWAT (SWAT 모형을 이용한 대청댐 유역의 기후인자에 따른 유출 및 유사량 민감도 평가)

  • Ye, Lyeong;Chung, Se-Woong;Lee, Heung-Soo;Yoon, Sung-Wan;Jeong, Hee-Young
    • Journal of Korean Society on Water Environment
    • /
    • v.25 no.1
    • /
    • pp.7-17
    • /
    • 2009
  • Soil and Water Assessment Tool (SWAT) was used to assess the impact of potential future climate change on the water cycle and soil loss of the Daecheong reservoir watershed. A sensitivity analysis using influence coefficient method was conducted for two selected hydrological input parameters and three selected sediment input parameters to identify the most to the least sensitive parameters. A further detailed sensitivity analysis was performed for the parameters: Manning coefficient for channel (Cn), evaporation (ESCO), and sediment concentration in lateral (LAT_SED), support practice factor (USLA_P). Calibration and verification of SWAT were performed on monthly basis for 1993~2006 and 1977~1991, respectively. The model efficiency index (EI) and coefficient of determination ($R^2$) computed for the monthly comparisons of runoffs were 0.78 and 0.76 for the calibration period, and 0.58 and 0.65 for the verification period. The results showed that the hydrological cycle in the watershed is very sensitive to climate factors. A doubling of atmospheric $CO_2$ concentrations was predicted to result in an average annual flow increase of 27.9% and annual sediment yield increase of 23.3%. Essentially linear impacts were predicted between two precipitation change scenarios of -20, and 20%, which resulted in average annual flow and sediment yield changes at Okcheon of -53.8%, 63.0% and -55.3%, 65.8%, respectively. An average annual flow increase of 46.3% and annual sediment yield increase of 36.4% was estimated for a constant humidity increase 5%. An average annual flow decrease of 9.6% and annual sediment yield increase of 216.4% was estimated for a constant temperature increase $4^{\circ}C$.

Characteristics of Wave Attenuation with Coastal Wetland Vegetation (연안 습지식생에 의한 파랑감쇠 특성)

  • Lee, Seong-Dae
    • Journal of Wetlands Research
    • /
    • v.18 no.1
    • /
    • pp.84-93
    • /
    • 2016
  • As a transition region between ocean and land, coastal wetlands are significant ecosystems that maintain water quality, provide natural habitat for a variety of species, and slow down erosion. The energy of coastal waves and storm surges are reduced by vegetation cover, which also helps to maintain wetlands through increased sediment deposition. Wave attenuation by vegetation is a highly dynamic process and its quantification is important for understanding shore protection and modeling coastal hydrodynamics. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type as well as wave conditions. Wave attenuation characteristics were investigated under regular waves for rigid model vegetation. Laboratory hydraulic test and numerical analysis were conducted to investigate regular wave attenuation through emergent vegetation with wave steepness ak and relative water depth kh. The normalized wave attenuation was analyzed to the decay equation of Dalrymple et al.(1984) to determine the vegetation transmission coefficients, damping factor and drag coefficients. It was found that drag coefficient was better correlated to Keulegan-Carpenter number than Reynolds number and that the damping increased as wave steepness increased.

Assessment of Streamflow and Evapotranspiration Influence on the Climate Change under SRES A1B Scenario (기후변화에 따른 A1B 시나리오의 유출 및 증발산량 영향 평가)

  • Ahn, So-Ra;Park, Min-Ji;Park, Geun-Ae;Kim, Seong-Joon
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2008.05a
    • /
    • pp.1097-1101
    • /
    • 2008
  • 본 연구에서는 SLURP 수문모형을 이용하여 미래기후와 예측된 토지이용자료 및 식생의 활력도를 고려한 상태에서 하천유역의 유출 및 증발산량에 미치는 영향을 분석하였다. 경안천 상류유역($260.04\;km^2$)을 대상유역으로 선정하여 4개년(1999-2002) 동안의 일별 유출량 자료를 바탕으로 모형의 보정(1999-2000)과 검증(2001-2002)을 실시하였다. 모형의 보정 및 검정 결과 Nash-Sutcliffe 모형효율은 0.79에서 060의 범위로 나타났다. 미래 기후자료는 IPCC(Intergovernmental Panel on Climate Change)에서 제공하는 A1B 기후변화시나리오의 MIROC3.2 hires, ECHAM5-OM, HadCM3 모델의 결과값을 이용하였다. 먼저 과거 30년 기후자료(1977-2006, baseline)를 바탕으로 각 모델별 20C3M(20th Century Climate Coupled Model)의 모의 결과값을 이용하여 강수와 온도를 보정한 뒤 Change Factor Method로 Downscaling하였다. 미래 기후자료는 2020s(2010-2039), 2050s(2040-2069), 2080s(2070-2099)의 세 기간으로 나누어 분석하였다. 미래 토지이용은 과거 시계열 Landsat 토지이용도를 이용하여 CA-Markov기법으로 예측된 토지이용을 사용하였으며, 미래의 식생정보 예측을 위하여 NOAA/AVHRR 위성영상으로부터 추출된 월별 NDVI(1998-2002)와 월평균기온간의 선형 회귀식을 도출하여 미래의 식생지수 정보를 추정하였다. 모형의 적용결과, 미래기후변화에 따른 연평균 하천유출은 현재보다 최대 2020s는 23.9%, 2050s는 40.7%, 2080s는 39.5% 증가하였다. 봄 강수량 패턴의 변화로 유출량 증가하는 것으로 나타났으며 여름에는 유출량은 감소하고 증발산량은 증가하는 결과를 보였다.

  • PDF

Estimation of Soil Erosion for Each Spatial Resolution on the Climate Change (기후변화에 따른 공간해상도별 토양유실량 평가)

  • Lee, Mi-Seon;Park, Jong-Yoon;Jung, In-Kyun;Kim, Seong-Joon
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2008.05a
    • /
    • pp.529-533
    • /
    • 2008
  • 본 연구는 미래기후변화가 공간해상도(5, 10, 30m)에 따른 토양유실량의 변화에 미치는 영향을 분석하고 자하였다. 연구대상지역은 경안천 최상류에 위치한 $1.16km^2$의 농촌 소유역을 대상으로 공간해상도별(5, 10, 30m) RS 및 GIS 자료를 생성하고, GIS 기반의 RUSLE(Revised Universal Soil Loss Equation) 모형을 채택하여 토양유실량을 분석하였다. 기후변화 시나리오는 IPCC(Intergovernmental Panel on Climate Change)에 서 제공하는 GCM(Global climate model) 중에서 MIROC3.2 hire의 A1B, B1 시나리오를 이용하였으며, 과거 30년간(1977-2006)의 기상자료 통계정보를 기준으로 Change Factor Downscaling 기법을 적용하여 2020s년 (2010-2039), 2050s년(2040-2069), 2080s년(2069-2099) 전후의 각 30년간의 미래 강우량을 재생산하여 사용하였다. 그 결과 강수량은 2080s년에 A1B 시나리오의 경우 연평균 강수량은 270.37mm, 최대 강수량은 65.71mm 증가하였고, B1 시나리오의 경우 연평균 강수량은 37.11mm, 최대 강수량은 48.46mm 증가하는 것으로 나타났다. 구축한 미래 강우량을 RUSLE 인자 중 R 인자에 적용하여 2020s년, 2050s년, 2080s년의 토양유실량을 분석한 결과, 미래강수량이 증가함에 따라 공간해상도별 토양유실량도 증가하는 것으로 분석되었다. 평균토양유실량을 시나리오별로 보면, A1B 시나리오의 경우 2080s을 기준으로 1/5,000 scale에서는 약 0.18 ton/ha/year, 1/25,000 scale에서는 약 0.07 ton/ha/year, 1/50,000 scale에서는 약 0.07 ton/ha/year의 유실량이 각 공간해상도별로 증가하였다. B1 시나리오의 경우 2080s을 기준으로 1/5,000 scale에서는 약 0.03 ton/ha/year, 1/25,000 scale에서는 약 0.01 ton/ha/year, 1/50,000 scale에서는 약 0.01 ton/ha/year의 토양유실량이 증가한 것으로 분석되었다.

  • PDF

Activation of Matrix Metalloproteinases-9 after Photothrombotic Spinal Cord Injury Model in Rats

  • Jang, Jae-Won;Lee, Jung-Kil;Kim, Soo-Han
    • Journal of Korean Neurosurgical Society
    • /
    • v.50 no.4
    • /
    • pp.288-292
    • /
    • 2011
  • Objective : Matrix metalloproteinases (MMPs), especially MMP-2 and MMP-9 have been known to play an important role in secondary inflammatory reaction after spinal cord injury (SCI). The aim of this study was to investigate the expression and activity of MMP-2 and MMP-9 and to determine their relationship with disruption of endothelial blood-barrier after photochemically induced SCI in rats. Methods : Female Sprague-Dawley rats, weighing between 250 and 300 g (aged 8 weeks) received focal spinal cord ischemia by photothrombosis using Rose Bengal. Expressions and activities of MMP-2 and MMP-9 were assessed by Western blot and gelatin zymography at various times from 6 h to 7 days. Endothelial blood-barrier integrity was assessed indirectly using spinal cord water content. Results : Zymography and Western blot analysis demonstrated rapid up-regulation of MMP-9 protein levels in spinal cord after ischemic onset. Expressions and activities of MMP-9 showed a significant increased at 6 h after the photothrombotic ischemic event, and reached a maximum level at 24 h after the insult. By contrast, activated MMP-2 was not detected at any time point in either the experimental or the control groups. When compared with the control group, a significant increase in spinal cord water content was detected in rats at 24 h after photothrombotic SCI. Conclusion : Early up-regulation of MMP-9 might be correlated with increased water content in the spinal cord at 24 h after SCI in rats. Results of this study suggest that MMP-9 is the key factor involved in disruption of the endothelial blood-barrier of the spinal cord and subsequent secondary damage after photothrombotic SCI in rats.

The Quantitative Analysis in terms of the Requisite for Logistics Support of the War History using Simulation Moscow Expedition of Napoleon (시뮬레이션을 이용한 전쟁사 군수지원 요소의 정량적 분석 : 나폴레옹의 모스크바 원정 사례 연구)

  • Jung, Won-Il;Byun, Mu-Hyun;Cho, Sung-Jin;Kang, Sung-Jin
    • Journal of the military operations research society of Korea
    • /
    • v.37 no.1
    • /
    • pp.27-38
    • /
    • 2011
  • Purpose that studies the war history is to prevent the war in the advance through instruction that is gotten by understanding the past war and in case of emergency, it is to win victory in the war from the enemy by doing not commit a same mistake like the past war. For these reasons, many studies about the war history have proceeded continuously in domestic and outside the country, and those are being carried out in present. However, most of studies of the war history have been analyzed only on qualitative analysis. In this study, we want to suggest quantitative analysis method using simulation with qualitative analysis. As an example of study, we quantitatively analyzed the importance of logistics support on the Moscow expedition of Napoleon. Also, on the basis of this, we found failure factor of logistics support of Napoleon force and through this, deduced instruction. There is meaning that this paper suggested quantitative analytical method in terms of study of the war history with qualitative analytical method.

Factors Influencing Changes in Quality of Life in Patients undergoing Hematopoietic Stem Cell Transplantation: A Longitudinal and Multilevel Analysis (다층모형을 적용한 조혈모세포이식 환자의 삶의 질 변화 영향요인)

  • Song, Chi Eun;So, Hyang Sook
    • Journal of Korean Academy of Nursing
    • /
    • v.45 no.5
    • /
    • pp.694-703
    • /
    • 2015
  • Purpose: This study was a prospective longitudinal study to identify changes in quality of life in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). It was based on Roy's adaptation model. Methods: The questionnaires were administered before HSCT, 30 and 100 days after HSCT. Of the 48 potentially eligible patients, 44 (91.7%) participated in the study and 40 (90.9%) completed the questionnaires at 100 days after HSCT. Multilevel analysis was applied to analyze changes in quality of life. Results: Overall, quality of life showed a decreasing tendency from pre-HSCT to 100 days after HSCT. The adaptation level of participants was compensatory. Type of conditioning was the significant factor influencing quality of life before HSCT (${\beta}_{00}$=79.92, p <.001; ${\beta}_{01}$= - 12.64, p <.001) and the change rate of quality of life (${\beta}_{10}$= - 1.66, p =.020; ${\beta}_{11}$=2.88, p =.014). Symptom severity (${\beta}_{20}$= - 1.81, p =.004), depression (${\beta}_{30}$= - 0.58, p =.001), social dependency (${\beta}_{40}$= - 0.35, p =.165), and loneliness (${\beta}_{50}$= - 0.23, p =.065) had a negative effect on changes in quality of life. Symptom severity and depression were statistically significant factors influencing changes in quality of life. Conclusion: According to the results of this study, the development of nursing intervention is needed to improve quality of life in patients undergoing allogeneic hematopoietic stem cell transplantation in the early immune reconstruction period. The interventions should include programs to enhance coping capacity and programs to help control symptom severity and depression. Also these interventions need to be started from the beginning of HSCT and a multidisciplinary approach would be helpful.

Development and Validation of a Tool for Evaluating Core Competencies in Nursing Cancer Patients on Chemotherapy (항암화학요법을 받는 암환자 간호핵심역량 측정도구 개발 및 타당화)

  • Kim, Sung Hae;Park, Jae Hyun
    • Journal of Korean Academy of Nursing
    • /
    • v.42 no.5
    • /
    • pp.632-643
    • /
    • 2012
  • Purpose: This study was done to develop tool to evaluate the core competencies regarding nursing cancer patients on chemotherapy, and to verify the reliability and efficacy of the developed tool. Methods: A tool to evaluate the core competencies was developed from a preliminary tool consisting of 112 items verified by expert groups. The adequacy of the preliminary tool was analyzed and refined to the final evaluation tool containing 76 items in 8 core competencies and 18 specific competencies. The evaluation tool is in the form of a self-report, and each item is evaluated according to a 3-point scale. From September 22 to October 14, 2011, 349 survey responses were analyzed using SPSS 20.0 and the WINSTEPS program that employs the Rasch model. Results: Results indicated that there were no inappropriate items and the items had low levels of difficulty in comparison with the knowledge levels of the study participants. The results of factor analysis yielded 18 factors, and the reliability of the tools was very high with Cronbach's ${\alpha}$=.97. Conclusion: The results of this study can be used for training and evaluation of core competencies for nursing cancer patients, and for standardizing nursing practices associated with chemotherapy.

A Study on Relationship Between TMD and Skeletodental Form in Long Face Patterns (장안모군에서 악관절 장애와 악안면 골격형태에 대한 연구)

  • Tae, Ki-Chul;Kim, Sang-Cheol
    • The korean journal of orthodontics
    • /
    • v.29 no.1 s.72
    • /
    • pp.37-49
    • /
    • 1999
  • Forty-four females with normal temporomandibular joint were compared with fifty-one females with abnormal temporomandibular joint. An orthodontic study model and lateral cephalometric radiographic were used to investigate the relationship between TMD group and non-TMD group in long face patterns. The result were followed that ; 1. There were no significant in overbite and overjet amount. 2. A mandibular 1'st molar inclination and height to the mandibualr plane were more mesial inclined in TMD groups. 3. The functional factors, which were craniocervical posture , tongue posture and hyoid bone position, were no significant.

  • PDF

Epidemiological Characteristics of Gallbladder Cancer in Jeju Island: A Single-Center, Clinically Based, Age-Sex-Matched, Case-Control Study

  • Cha, Byung Hyo
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.18
    • /
    • pp.8451-8454
    • /
    • 2016
  • Background: Gallbladder cancer (GBC) is a rare but highly invasive malignancy characterized by poor survival. In a national cancer survey, the age-standardized incidence rate of GBC was highest in Jeju Island among the 15 provinces in South Korea. The aim of this descriptive epidemiological study was to suggest the modifiable risk factors for this rare malignant disease in Jeju Island by performing an age-sex-matched case-control study. Materials and Methods: The case group included patients diagnosed with GBC at the Department of Internal Medicine of Cheju Halla General Hospital, Jeju, South Korea, within the 5-year study period. The control group consisted of age-sex-matched subjects selected from among the participants of the health promotion center at the same institute and in the same period. We compared 78 case-control pairs in terms of clinical variables such as histories of hypertension, diabetes, vascular occlusive disorders, alcohol and smoking consumption, obesity, and combined polypoid lesions of the gallbladder (PLG) or gallstone diseases (GSDs). Results: Among the relevant risk factors, alcohol consumption, parity ${\geq}2$, PLG, and GSDs were significant risk factors in the univariate analysis. PLG (p < 0.01; OR, 51.1; 95% confidence interval [CI], 2.98-875.3) and GSD (p < 0.01; OR, 54.9; 95% CI, 3.00-1001.8) were associated risk factors of GBC in the multivariate analysis with the conditional logistic regression model. However, we failed to find any correlation between obesity and GBC. We also found a negative correlation between alcohol consumption history and GBC in the multivariate analysis (p < 0.01; OR, 0.06; 95% CI, 0.01-0.31). Conclusions: These results suggest that combined PLG and GSDs are strongly associated with the GBC in Jeju Island and mild to moderate alcohol consumption may negatively correlate with GBC risk.