• The Journal of Engineering Geology
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• v.17 no.1 s.50
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• pp.125-133
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• 2007

The environmental and geotechnical properties are investigated to the 8th landfill area made of only sewage sludge in Nanji-Do. To do this, the soils are sampled in this area, and leaching tests, heavy metal content tests, and so on are performed to research the environmental properties. As the result of heavy metal content tests, Pb, Zn, Cu, Ni, Cd and Cr were leached from the sewage sludge. Because the leaching concentration of Cu is more than the standard value of California state, Cu content have to bring down during the recycling of the sewage sludge. Meanwhile, a series of tests concerning specific gravity, liquid and plastic limits, compaction, permeability and shear strength is performed to research the geotechnical properties. The sewage sludge is consisted of sand, silt and clay, and is classified into non-organic silt or organic clay with 42.3% of plastic index. As the result of compaction test, it is expected that the compaction effect according to variation of water contents is low relatively because the dry unit weight is low and the curve of compaction forms flatness. Also, as the result of direct shear tests, the cohesion is $0.058kg/cm^2$, and the internal friction angle is $14^{\circ}$. Taking everything into consideration, the various problems are happening in case of recycling the sludge like the cover layer of landfill and so on because the compaction is bad, and the shear strength is low. Also, it is expected that the ground water pollution caused by leaching the heavy metal into the sludge. To do recycling the sewage sludge in this site, supplementary and treatment programs should be prepared.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.166-172
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• 2016

Accurate understanding of land surface is essential to analyze energy exchanges between earth surface and atmosphere. For the quantization of energy fluxes, the various researches about Land Surface Model(LSM) have been progressed. Among the various LSMs, the researches using Common Land Model(CLM) and Variable Infiltration Capacity(VIC) model are performed briskly. The CLM which is advanced LSM can calculate realistic results with few user defined parameters. The VIC model which is also typical LSM is widely used for estimation of energy fluxes and runoff in various fields. In this study, the energy fluxes which are net radiation, sensible heat flux, and latent heat flux were estimated using CLM and VIC model at Southern Sierra-Critical Zone Observatory(SS-CZO) site in California, United States. In case of net radiation and sensible heat flux, both models showed good agreement with observations, however, the CLM showed underestimated patterns of net radiation and sensible heat flux during precipitation period. In case of latent heat flux, the CLM represented better estimation of latent heat flux than VIC model which underestimated the latent heat flux. Through the estimation of energy fluxes and analysis of models' pros and cons, the applicability of CLM and VIC models and need of multi-model application were identified.

• Journal of the Korean earth science society
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• v.41 no.3
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• pp.238-247
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• 2020

This study simulated strong ground motion waveforms in the southern Korean Peninsula, based on the physical earthquake modeling of the Southern California Earthquake Center (SCEC) BroadBand Platform (BBP). Characteristics of intensity attenuation were investigated for M 6.0-7.0 events, incorporating the site effects. The SCEC BBP is software generates broadband (0-10 Hz) ground-motion waveforms for earthquake scenarios. Among five available modeling methods in the v16.5 platform, we used the Song Model. Approximately 50 earthquake scenarios each were simulated for M 6.0, 6.5, and 7.0 events. Representative metrics such as peak ground acceleration (PGA) and peak ground velocity (PGV) were obtained from the synthetic waveforms that were simulated before and after the consideration of site effects (V_S30). They were then empirically converted to distribution of instrumental intensity. The intensity that considers the site effects is amplified at low rather than high V_S30 zones.

• Korean Journal of Construction Engineering and Management
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• v.14 no.6
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• pp.3-13
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• 2013

The converted accident rates that included in Pre-Qualification (PQ) are to evaluate the results of accidents which have occurred. Therefore, it is demanded the development of proactive evaluation contents to evaluate the safety management activities and efforts on construction companies. The purpose of this study is to provide basic data for the establishment of proactive evaluation contents at public construction project in Korea through the collected and analyzed the PQ documentation applied by public agencies in Los Angeles, USA. The results indicated that diverse reactive safety evaluations are implemented to examine accidents which occurred in past projects such as occupational health insurance, regulation violation. And also, when the accidents occurred, it is evaluated the proactive safety management actions such as safety education, accident prevention programs, and safety management plans are reflected on the evaluation. Thus, if proactive safety related evaluation contents are established and reflected in PQ examinations together with diverse existing reactive safety evaluations considering converted accident rates, not only the existing function of converted accident rates can be reinforced but also businesses' active safety management activities can be induced and decreases in the construction industry's accident rate can be expected.

• Korea Journal of Hospital Management
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• v.23 no.1
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• pp.87-106
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• 2018

Objective: The objective of this study is to examine the association between process quality of inpatient care and risk-adjusted, thirty-day potentially preventable hospital readmission (PPR) rates. Data Sources/Study Setting: This was an observational cross-sectional study of nonfederal acute-care hospitals located in two states California and Florida, discharging Medicare patients with a principal discharge diagnosis of heart failure, acute myocardial infarction, or pneumonia January through December 31, 2007. Data were obtained from the Healthcare Cost and Utilization Project State Inpatient Database of the Agency for Healthcare Research and Quality, Centers for Medicare and Medicaid Services Hospital Compare database, and the American Hospital Association Annual Survey of Hospitals. Study Design: The dependent variable of this study is condition-specific, risk-adjusted, thirty-day potentially preventable hospital readmission (PPR). 3M's PPR software was utilized to determine whether a readmission was potentially preventable. The independent variable of this study is hospital performance for process quality of inpatient care, measured by hospital adherence to recommended processes of care. We used multivariate hierarchical logistic models, clustered by hospitals, to examine the relationship between condition-specific, risk-adjusted, thirty-day PPR rates and process quality of inpatient care, after taking clinical and socio-demographic characteristics of patients and structural and operational characteristics of hospitals into account. Findings: Better performance on the process quality metrics was associated with better patient outcome (i.e., low thirty-day PPR rates) in pneumonia, but not generally in two cardiovascular conditions (i.e., heart failure and acute myocardial infarction). Practical Implication: Adherence to the process quality metrics currently in use by CMS is associated with risk-adjusted, thirty-day PPR rates for patients with pneumonia, but not with cardiovascular conditions. More evidence-based process quality metrics closely linked to 30-day PPR rates, particularly for cardiovascular conditions, need to be developed to serve as a guideline to reduce potentially preventable readmissions.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.59-64
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• 2008

We need to use the strength of each Species Distribution Model(SDM) because presence location data were only collected due to time and economic limitations in Korea. This study investigated and compared GAM(Generalized Additive Model) which is one of presence-absence models with Maxent(Maximum Entropy Model) which is one of presence only models according to location data(presence/absence data). The target species was Fisher(Martes pennanti) which is an endangered species in California, USA. We implemented environmental data such as topography, climate and vegetation, and applied models to sub-regions and study area. The results of this study were as follows. Firstly, GAM which used real presence and absence data was better than GAM which used pseudo-absence data and Maxent which used presence-only data. Secondly, Maxent was better than GAM when presence-only data were used. Lastly, each model which applied to different regions didn't predict other area well due to the difference of habitat environment and over-predicted outside of study area. We need to select an optimal model to predict a suitable habitat according to the type and distribution of location data.

• Journal of Energy Engineering
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• v.19 no.1
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• pp.8-15
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• 2010

As environmental friendly energy system, distributed micro gasturbine is focused on new energy source for overcoming brand new construction area of power generation. This distributed micro gasturbine system has the powerful characteristics as belows; 1) environmental friendly features NOx < 9 ppm, noise < 65 db 2) various fuel flexbility which is used such as natural gas, diesel, low calory new & renewable fuel, kerosene. 3) high specific output power based on small area and is avilable for very easy and compact installation. There are many new installation sites in USA and Japan from 1998. On the other hand the exhisting large power system was constructued by the sea side, this compact power system is now installed by enduser in downtown area and supplying combined heat & power, has the various apllication on-site power generation. In recently, there is the very important issue for new & reliablbe energy development and spreading out. This paper represent as belows for important system characteristics; 1) grid connection modeling 2) system operation characteristics 3) on-site operation result and evaluation output of power quality analysis.

• Journal of Korean Public Health Nursing
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• v.10 no.1
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• pp.39-57
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• 1996

미국은 이제까지 서구 백인문화 중심적으로 간호학을 발전시켜왔다. 그러나 국제적인 세계화 흐름과 함께 이제까지 경시되어 왔던 소수 민족들에게 차츰 관심을 모으고 있다. 이러한 간호학의 추세와 함께 재미 한인들의 증가는 간호학 내의 한인들에 대한 문화적 지식의 확대를 필요로 하게 하였다. 이민이라는 과정을 통해서 이민자들은 새로운 가치관. 태도. 사회적 규범을 획득하게 되는데. 이러한 변화는 신체적. 정신적 건강에 부정적으로 영향을 미치는 것으로 보고되고 있다. 또한 이러한 이민 적응과정에서 오는 어려움 들은 이민자 들이 건강관리를 효과적으로 하지 못하게 하는 주원인으로 보고되고 있다. 이 연구에서는 재미 한인들의 건강관리실천을 그들의 초기 이민 과정에서 겪게 되는 여러 경험에 초점을 맞추면서 면담조사와 사례 연구를 통하여 살펴보았다. 임의 표본 추출된 미국 캘리포니아주 오클랜드에 있는 한 한인 교회의 20명의 교민들을 대상으로 그들의 초기 이민경험과 건강관리 실천에 관한 면담 조사가 이루어졌으며 대상자 중 3인을 대상으로 하여 사례 연구가 이루어졌다. 연구 결과, 재미 한인들은 타이민자들에 비해 소규모 사업에 종사하는 경우가 많고 높은 취업 율에 비해 낮은 수인을 가지는 것으로 나타났다. 한인들은 타이민자들에 비해 좀 더 보수적이며 그들의 문화와 관습을 가능한 한 고수하는 것으로 나타났다. 또한 한인들은 사회 참여와 대인 관계에 있어서 한인 사회에만 한정되게 활동하는 것으로 나타났다. 재미 한인들은 한인 사회 내에서 강력한 사회적 유대관계를 유지하는 것으로 나타났으며, 가족의 영향력이 타민족들에 비하여 강한 것으로 나타났다 언어 장벽이 가장 큰 문제로 보고되고 있으며 비록 성공적으로 미국 사회에 적응을 하더라도 계속적인 경제적인 생존 노력과 사회적으로 소외된 그들의 위치는 그들의 삶을 계속해서 어렵게 하는 것으로 나타났다. 이러한 초기 이민 적응과정에서 오는 어려움 들은 그들의 건강을 비효과적으로 관리하게 만드는 것으로 나타났다. 첫째, 적절한 통역자를 사전에 선정, 이용함으로써 적절한 간호를 제공할 수 있도록 하여야겠다. 둘째. 한인을 대하는 간호 제공자들은 한인에 대한 문화적 지식을 겸비하고 그 지식에 근거를 둔 문화적으로 적절한 간호를 제공하여야 할 것이다. 셋째, 간호 제공자들은 한인들의 치료법 혼용을 이해하고 동시에 여러 치료법을 사용하는 경우. 잘 살펴서 적절한 조치를 취해야 할 것이다. 넷째, 가족관계를 사정하고 적절히 가족 구성원을 간소 목적을 위하여 사용할 수 있어야 하겠다 마지막으로 이들 내의 위험 집단을 우선적으로 파악. 접근하여야 할 것이다. 위험 집단으로는 경제적 문제로 적절한 의료 이용을 할 수 없는 저소득층, 문화적으로 열등한 위치에 있는 여성층과 초기 이민 적응에 가장 문제를 일으킬 소지가 있는 노년층을 들 수 있겠다. 이 연구는 몇 가지 제한점을 가진다. 첫째. 연구 대상자 선정이 어려워서 자원자를 대상으로 연구가 행해졌다. 둘째. 적은 수의 연구 대상자를 대상으로 연구가 행해졌다. 셋째. 연구기간이 짧았던 까닭에 좀더 상세한 사례 연구가 이루어질 수 없었다 좀 더 신뢰할 수 있는 표본 추출 방법을 통하여 선정된, 많은 연구 대상자를 가지고, 심도 있는 연구가 추후 반복적으로 이루어져야 할 것이다.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.98-108
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• 2006

The climate of urban area is an unstable type with considerable seasonal variation in precipitation wind speed, and temperature and it grows worse. Besides, ozone is a serious air pollutant in most of large cities. So worldwide, some of large cities are investing in forestry options to offset their climate problems, but lack of information has hindered comparisons of urban un cost effectiveness to other options. This research intends to study the economic benefits of tree shading of 19 parking lots in UCD campus. The economic benefits of tree shading are air conditioning savings, air quality, stormwater run-off, and other benefits. Especially, this study focuses how much the economic benefit of parking lot shading has been increased from 1995 to 2003 year by aerophoto. Some data on dimensions of parking lots and the number, size, tree species, and location of trees around each parking lot was inventoried. Two aerophotos(1995,2003) were used in order to analyze the increasement of tree canopy in 19 parking lots for 8 years. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy. For example, coverage of trees help to save cooling energy by blocking solar radiation reaching parking cars and building structures through shading, and creating cool micro-climates through evapotranspiration. They also reduce heating demand by decreasing air infiltration and heat conduction out of the interior of buildings. Proper arrangement of vegetation over the parking lots can reduce cooling and heating costs. So proper planting design around hard space paving including species selection and location can significantly save cooling and heating energy. And a reduction in car and building's heating and cooling costs results in the reduction in energy demand which causes to emissions of air pollutants. Total increased tree canopy from 1995 to 2003 is $8,470.45m^2$ and the economic benefits is US$ 5,282.10. The economic benefit of one tree has been US$ 7.21 for 8 years. And an annually increased benefit is US$ 0.9 per a tree. If this kind of study is applied to studying the economic benefits of tree canopy in parking lots of Korea, it could result in guidelines of tree planting of parking lots. Because the trees selected for planting in parking lots were not suitable for an environment, the guidelines should contain a recommended list of trees. The guidelines should propose the shading percentage of parking lot when we plan a parking lot and contain the maintenance of trees in order to maximize the economic benefits of tree canopy.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.283-291
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• 2013

This experiment was carried out for the selection of suitable cultivars on the green and fairway at the mountain area. The climate data showed that differences of altitude influenced greater than latitude on temperature and rainfall when compared with 3 areas of the central of Gyeong-gi and Yeong-seo, and the mountain area at Yeong-seo. The plot was prepared with the USGA profiles for green and modified California style for fairway at the mountain golf course in Wonju, Korea. The growth characteristics were compared on two different profiles for 3 years of growing seasons after seeding with 5 creeping bentgrass cultivars. 'T-1' and 'CY-2' showed a rapid greenup compare with other cultivars in spring of 2010 with the both green and fairway mowing height. However, 'Penncross' resulted the slowest among cultivars. 'T-1' showed the most prominent visual quality of overall rate and the deepest root length after one year of seeding, while 'Penncross' showed an excellent result of root length and weight during summer season. However, 'Penn A-1' had an imperial result in that season. Comparison of the growth characteristics under green and fairway conditions, 'T-1' and 'CY-2' showed exellent overall results at the mountain area at Yeong-seo area in Korea.