• 한국환경과학회지
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• 제15권5호
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• pp.461-469
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• 2006

As a frontier of Sustainable Basin Research Initiative, we commenced a scenario-driven planning and evaluation research project which is to identify the strategic policy scenarios. As a part of the project, this study attempts to estimate the ecological impacts of land cover changes using landscape indices at the whole basin level. We analyzed spatio-temporal characteristics of natural area including forest, agricultural land, water area, barren which play an important role in nature-friendly sustainable watershed management. The results of analysis shelved that the size and diversity of natural area have been reduced, while patch number and isolation have been increased in proportion to urbanization in 1974, 1995 and four future scenarios in the Ara River Basin. Also, we estimated that the natural area could be conserved to some degree in the SD or DE scenarios with a concept of environment-friendly development and lifestyle. Various strategic environment policies may be evaluated and designed on the basis of the method, that is, scenario approach and landscape ecological analysis suggested in this study.

• 한국조경학회지
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• 제35권6호
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• pp.37-47
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• 2008

Recently, reckless exploitation of land resources without much consideration for the environmental value of the land has been witnessed to accommodate the ever-increasing demands for regional development. Fragmentation due to land development is a major reason for the declining biodiversity in forest ecosystems. The purposes of this study were (1) to investigate the relationship between the factors of land development and forest fragmentation in 13 watersheds of a metropolitan area and (2) to suggest a forest management plan through the relationship. We carried out a factor analysis to determine explanatory axes of forest fragmentation, and then conducted a correlation analysis between the factor scores and the factor of land development, such as the rate of built-up areas, road density, number of built-up patches, and area of housing developments. The first explanatory axis represented stability of landscape highly related with the rate of the built-up area and road density. The second axis represented the level of fragment highly related with a number of built-up patches. Forest fragmentation patterns of the 13 watersheds were classified for the similarity in forest fragmentation. This study presents the forest management plans including distribution and level of land development and forest conservation.

• 한국항행학회논문지
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• 제19권2호
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• pp.161-167
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• 2015

본 연구는 수시로 변경 및 갱신되는 국가 직무능력 표준 (NCS; national competency standards) 학습모듈을 제공하는 시스템을 제안하였다. 제안 시스템의 프로비저닝(provisioning)서버는 학습모듈을 제공하며, 관리서버는 장애관리, 빌링, 요청관리, 통계 및 집계등을 수행하며, 타겟서버는 도메인을 통하여 프로비저닝서버에 학습모듈을 요청한다. 제안 시스템은 프로비저닝서버와 타겟 서버의 도메인 일치 여부를 판단하는 CORS (cross-origin resource sharing) 기반 필터를 이용하여, 학습모듈의 제공을 결정하였다. 제안 시스템은 신규 갱신 또는 삭제되는 NCS기반 학습모듈에 대해 원격으로 패치 및 유지 보수할 수 있다. 또한, 기존 교육 관련 시스템과 연계하여 콘텐츠를 제공할 수 있으며, 타겟서버 도메인에 대한 관리가 가능하여 향후 확장기능을 도입하여 활용할 수 있다.

• 디지털융복합연구
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• 제13권10호
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• pp.147-155
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• 2015

본 연구의 목적은 시장에 출시된 온라인 게임의 운영과정에서 오류를 수정하고 게임성능을 제고하기 위해 제공하는 콘텐츠 업데이트 또는 패치서비스가 실질적으로 게이머의 플레잉 시간에 영향을 미치는지 여부를 계량적으로 분석해 보는 데에 있다. 이를 위해 온라인게임 개발회사가 게임콘텐츠와 관련하여 추가하는 콘텐츠 업데이트를 두 가지 유형으로 구분하여 업데이트 후 플레잉 시간에 통계적으로 유의한 영향을 미치는지 여부를 회귀분석을 이용하여 분석하였다. 분석 결과, 콘텐츠 업데이트 외에 추가적인 독립변수로 설정한 출시 후 경과시간은 플레잉 시간 변동에 음의 유의한 영향을 미치는 것을 나타났지만, 새로운 게이머들을 유인하고 기존 게이머들의 플레잉 시간을 증가시키기 위해 제공하는 콘텐츠 생성이나 조절은 플레잉 시간 증가에 유의한 영향을 미치지 않은 것으로 나타났다. 연구결과가 제시하는 게임 디자인 측면에서의 시사점을 결론으로 제시하였다.

• 디지털융복합연구
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• 제19권3호
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• pp.371-378
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• 2021

본 연구의 목적은 클로로겐산이 함유된 피부 패치를 피부에 부착하여 체지방과 체중에 미치는 변화를 규명하여, 유용성을 평가하는 것이다. 시험군 8명, 대조군 8명으로 총 16명의 대상자가 연구에 참여하였고, 연구 기간은 2020년 08월 03일부터 2020년 08월 31일까지 4주간 실시하였다. 군-간 효과검정 결과 체지방의 변화는 전체적으로 유의한 차이가 없었으나(F=4.38, p<.055), 1주 후와 4주 후 검사에서는 의미있는 변화(p<.001)가 있었다. 또한, 체중은 유의미한 차이로 시험군이 대조군보다 체중 감소가 큰 것으로 나타났다(F=9.43, p<.008). 이번 연구의 결과는 비만 관련 연구에 패치를 적용한 예비연구로써 의미가 있다고 할 수 있으며, 연구의 결과가 향후 연구될 피부 패치 연구의 기초 자료로 활용될 수 있을 것으로 판단된다.

• The Korean Journal of Pain
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• 제35권2호
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• pp.224-230
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• 2022

Background: An epidural blood patch (EBP) is a procedure to treat intracranial hypotension that does not respond to conservative treatment. EBPs are commonly repeated when the symptoms persist. In this study, we used a large single-center retrospective cohort and evaluated the factors associated with repeated EBPs. Methods: From January 2010 to December 2020, a total of 596 patients were treated with EBPs for intracranial hypotension. We evaluated the factors associated with repeated EBPs in the entire population, in patients with spontaneous intracranial hypotension (SIH), and in those with available myelographies. Results: In a total of 596 patients, 125 (21.1%) patients required repeated EBPs, and 96/278 (34.5%) in SIH and 29/314 (9.2%) in iatrogenic population. In patients with SIH, international normalized ratio (INR) and cerebrospinal fluid (CSF) leakage on myelographies consistently exhibited significant associations (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.02-1.87; P = 0.043 and OR, 2.18; 95% CI, 1.28-3.69; P = 0.004). In patients with iatrogenic injury, INR and CSF leakage on myelogram did not show difference in repeated EBPs. Conclusions: Repeated EBPs may be more frequently required in patients with SIH. Prolonged INR and CSF leakage were associated with repeated EBPs in patient with SIH. Further studies are needed to determine factors associated with repeated EBP requirements.

• The Plant Pathology Journal
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• 제38권3호
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• pp.182-193
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• 2022

Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.

• 한국물환경학회지
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• 제24권2호
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• pp.185-194
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• 2008

There is increased soil erosion potential at highland agricultural crop fields because of its topographic characteristics and site-specific agricultural management practices performed at these areas. The agricultural upland fields are usually located at the sloping areas, resulting in higher soil loss, pesticides, and nutrients in case of torrential rainfall events or typhoon, such as 2002 Rusa and 2003 MaeMi. At the highland agricultural fields, the soil reconditioning have been performed every year to decrease damage by continuous cropping and pests. Also it has been done to increase crop productivity and soil fertility. The increased amounts of soil used for soil reconditioning are increasing over the years, causing significant impacts on water quality at the receiving water bodies. In this study, the field investigation was done to check soil reconditioning status for potato, carrot, and cabbage at the Doam-dam watershed. With these data obtained from the field investigation, the Soil and Water Assesment Tool (SWAT) model was used to simulate the soil loss reduction with environment-friendly and agronomically enough soil reconditioning. The average soil reconditioning depth for potato was 34.3 cm, 48.3 cm for carrot, and 31.2 cm for cabbage at the Doam-dam watershed. These data were used for SWAT model runs. Before the SWAT simulation, the SWAT ArcView GIS Patch, developed by the Kangwon National University, was applied because of proper simulation of soil erosion and sediment yield at the sloping watershed, such as the Doam-dam watershed. With this patch applied, the Coefficient of Determination ($R^2$) value was 0.85 and the Nash-Sutcliffe Model Efficiency (EI) was 0.75 for flow calibration. The $R^2$ value was 0.87 and the EI was 0.85 for flow validation. For sediment simulation, the $R^2$ value was 0.91 and the EI was 0.70, indicating the SWAT model predicts the soil erosion processes and sediment yield at the Doam-dam watershed. With the calibrated and validated SWAT for the Doam-dam watershed, the soil erosion reduction was investigated for potato, carrot, and cabbage. For potato, around 19.3 cm of soil were over applied to the agricultural field, causing 146% of more soil erosion rate, approximately 33.3 cm, causing 146% of more soil erosion for carrot, and approximately 16.2 cm, causing 44% of more soil erosion. The results obtained in this study showed that excessive soil reconditioning are performed at the highland agricultural fields, causing severe muddy water issues and water quality degradation at the Doam-water watershed. The results can be used to develop soil reconditioning standard policy for various crops at the highland agricultural fields, without causing problems agronomically and environmentally.

• Journal of Ecology and Environment
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• 제34권2호
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• pp.237-249
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• 2011

Land-use changes due to the socio-economic environment influence landscape patterns and processes, which affect habitats and biodiversity. This study considers the effects of such land-use changes, particularly on the traditional rural "Maeul" forested landscape, by analyzing landscape structure and vegetation changes. Three study areas were examined that have seen their populations decrease and age over the last few decades. Five types of plant life-forms (Raunkier life-forms) were distinguished to investigate ecosystem function. Principle component analysis was used to understand vegetation dynamics and community characteristics based on a vegetation similarity index. Ordination analysis transformed species-coverage data was introduced to clarify vegetation dynamics. Landscape indices, such as area metrics, edge metrics, and shape metrics, showed that spatial heterogeneity has increased over time in all areas. Pinus densiflora was the main land-use plant type in all study areas but decreased over time, whereas Quercus spp. increased. Over a decade, P. densiflora communities shifted to deciduous oak and plantation. These findings indicate that the impact of human activities on the Maeul landscape is twofold. While forestry activities caused heavy disturbances, the abandonment of traditional human activities has led to natural succession. Furthermore, it can be concluded that the type and intensity of these human impacts on landscape heterogeneity relate differently to vegetation succession. This reflects the cause and consequence of patch dynamics. We discuss an approach for sustainable landscape planning and management of the Maeul landscape based on traditional management.

• Journal of Chest Surgery
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• 제17권4호
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• pp.620-624
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• 1984

The optimal surgical management of the coarctation of the aorta associated with ventricular septal defect is still debated. Sixteen patients with the coarctation of the aorta and VSD were operated upon between November, 1980 and September 1984 at Seoul National University Hospital. They were 11 males and 5 females. All presented between 5 months and 11.5 years of age [mean= 5.5 years]. Presenting symptoms were congestive heart failure in 11 [69%], cyanosis on crying in 3 [19%], and frequent upper respiratory infection in 2 [13%]. In all cases two-stage operation was applied except one in which one stage procedure was taken. Resection and end-to-end anastomosis was used in 3, Dacron graft in 5, Gortex graft in 1, and left subclavian flap angioplasty in 4. Remaining two were missed on the operating table before correction of the coarctation of the aorta. Overall operative death in repair of the coarctation of the aorta were 3[20%]. Among the 12 survivors after repair of the coarctation of the aorta, 4 required patch closure of VSD, 2 required primary closure, 2 showed spontaneous closure [17%], one [8%] showed decrease in its size, 3 were under observation. It might be safe to approach the coarctation of aorta plus VSD with initial repair of the coarctation of the aorta without banding of main pulmonary artery and later management of VSD as usual manner in simple VSD.