• Title/Summary/Keyword: 정성적 위험분석

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Selection of Optimal Models for Predicting the Distribution of Invasive Alien Plants Species (IAPS) in Forest Genetic Resource Reserves (산림생태계 보호구역에서 외래식물 분포 예측을 위한 최적 모형의 선발)

  • Lim, Chi-hong;Jung, Song-hie;Jung, Su-young;Kim, Nam-shin;Cho, Yong-chan
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.589-600
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    • 2020
  • Effective conservation and management of protected areas require monitoring the settlement of invasive alien species and reducing their dispersion capacity. We simulated the potential distribution of invasive alien plant species (IAPS) using three representative species distribution models (Bioclim, GLM, and MaxEnt) based on the IAPS distribution in the forest genetic resource reserve (2,274ha) in Uljin-gun, Korea. We then selected the realistic and suitable species distribution model that reflects the local region and ecological management characteristics based on the simulation results. The simulation predicted the tendency of the IAPS distributed along the linear landscape elements, such as roads, and including some forest harvested area. The statistical comparison of the prediction and accuracy of each model tested in this study showed that the GLM and MaxEnt models generally had high performance and accuracy compared to the Bioclim model. The Bioclim model calculated the largest potential distribution area, followed by GLM and MaxEnt in that order. The Phenomenological review of the simulation results showed that the sample size more significantly affected the GLM and Bioclim models, while the MaxEnt model was the most consistent regardless of the sample size. The optimal model overall for predicting the distribution of IAPS among the three models was the MaxEnt model. The model selection approach based on detailed flora distribution data presented in this study is expected to be useful for efficiently managing the conservation areas and identifying the realistic and precise species distribution model reflecting local characteristics.

Mitral Valve Repair for Mitral Regurgitation in Pediatric Patients (승모판폐쇄부전증를 가진 소아 환자에서 승모판성형술의 임상적 고찰)

  • Sim, Hyung-Tae;Yun, Tae-Jin;Park, Jeong-Jun;Jung, Sung-Ho;Uhm, Ju-Yeon;Jhang, Won-Kyoung;Kim, Young-Hwue;Ko, Jae-Kon;Park, In-Sook;Seo, Dong-Man
    • Journal of Chest Surgery
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    • v.40 no.8
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    • pp.536-545
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    • 2007
  • Background: Compared to adult patients, mitral regurgitation in pediatric patients is uncommon and it shows a wide spectrum of morphologic abnormalities. We retrospectively evaluated the midterm results of mitral valve repair in pediatric patients. Material and Method: Between December 1993 and August 2006, mitral valve repair was performed in 35 patients who were aged less than 18 years, The mean age was $5.3{\pm}5.3$ years and the mean body weight was $20,0{\pm}16.3\;kg$. 18 patients had associated cardiac anomalies. The most common pathologic finding was leaflet prolapse (n=17). The most common method of repair was the double orifice technique (n=15). Result: There was no early mortality. Eight patients underwent reoperation (24.2%), and five of them required mitral valve replacement. Among the four ring annuloplasty cases, two have developed mitral stenosis. Four out of the 14 double orifice cases required reoperation. One case of early mortality and one case of late mortality occurred in the reoperation cases. The 5-year survival rate and the freedom from reoperation rate were $93.3{\pm}4.6%$ and $76.1{\pm}8.2%$, respectively. The 5-year freedom from mitral valve replacement rate was $83.6{\pm}6.7%$. There was no significant risk factor for reoperation. Conclusion: The midterm results of mitral valve repair are very acceptable in pediatric patients compared to the adult cases, although the reoperation rate is slightly higher.