• Ocean and Polar Research
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• v.23 no.4
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• pp.433-440
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• 2001

Marine organisms in Antarctica live in an environment which exhibits variability in physical processes over a wide range of temporal scales, from seconds to millennia. This time scale tends to be correlated with the spatial scale over which a given process operates, though this relationship is influenced by biology. The way organisms respond to variability in the physical environment depends on the time-scale of that variability in relation to life-span. Short-term variations are perceived largely as noise and probably have little direct impact on ecology. Of much greater importance to organisms in Antarctica are seasonal and decadal variations. Although seasonality has long been recognised as a key feature of polar environments, the realization that decadal scale variability is important is relatively recent. Long-term change has always been a feature of polar environments and may be a key factor in the evolution of the communities we see today.

• Water Engineering Research
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• v.5 no.2
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• pp.81-99
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• 2004

Long term streamflow regime under virtual climate change scenario was examined. Rainfall forecast simulation of the Canadian Global Coupled Model (CGCM2) of the Canadian Climate Center for modeling and analysis for the IPCC SRES B2 scenario was used for analysis. The B2 scenario envisions slower population growth (10.4 billion by 2010) with a more rapidly evolving economy and more emphasis on environmental protection. The relatively large scale of GCM hinders the accurate computation of the important streamflow characteristics such as the peak flow rate and lag time, etc. The GCM rainfall with more than 100km scale was downscaled to 2km-scale using the space-time stochastic random cascade model. The HEC-HMS was used for distributed hydrologic model which can take the grid rainfall as input data. The result illustrates that the annual variation of the total runoff and the peak flow can be much greater than rainfall variation, which means actual impact of rainfall variation for the available water resources can be much greater than the extent of the rainfall variation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.4
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• pp.165-170
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• 2016

Long-term performance of the enthalpy exchange element is a topic of current interest due to the concern of possible performance degradation over time. In this study, a 350 CMH enthalpy recovery ventilator equipped with an enthalpy exchange element was installed in an office room, and the performance has been traced over the past 5 years. The appearance, overall dimension, thermal performance, leakage ratio and anti-bacterial performance were checked annually. Results showed that the change in thermal performance (sensible, latent and enthalpy efficiency) was negligible with periodic cleaning with an air gun. However, the leakage ratio increased with time, measuring 7.3% after 5 years. Anti-bacterial test revealed that no bacteria were found during the test period. The largest change in the dimension occurred at the middle location of the element, although the change was less than 2% of the initial value.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1802-1806
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• 2006

It is important to consider the effects of land-use changes on surface runoff, stream flow, and groundwater recharge. Expansion of urban areas significantly impacts the environment in terms of ground water recharge, water pollution, and storm water drainage. Increase of impervious area due to urbanization leads to an increase in surface runoff volume, contributes to downstream flooding and a net loss in groundwater recharge. Assessment of the hydrologic impacts or urban land-use change traditionally includes models that evaluate how land use change alters peak runoff rates, and these results are then used in the design of drainage systems. Such methods however do not address the long-term hydrologic impacts of urban land use change and often do not consider how pollutants that wash off from different land uses affect water quality. L-THIA (Long-Term Hydrologic Impact Assessment) is an analysis tool that provides site-specific estimates of changes in runoff, recharge and non point source pollution resulting from past or proposed land-use changes. It gives long-term average annual runoff for a land use configuration, based on climate data for that area. In this study, the environmental and hydrological impact from the urbanized basin had been examined with GIS L-THIA in Korea.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.782-788
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• 2014

Wind power generation has been viewed as a promising renewable energy to meet challenge of climate change. However, wind power is susceptible to climate change because previous investigation shows there are declining trends of the land surface wind speeds over middle and lower latitudes. Since long term variation trends is notably different from inter-annual random variation and could have notable impact on wind farm from planning perspective, observed meteorological data of Taiwan is investigated to find out long term variation trends of wind speed and its impact on wind power generation. It is discovered that wind speed in majority of stations in west coast of Taiwan have ascending trends while that of all investigated stations in east coast have descending trends. Since east of Taiwan is not suitable for wind power development for its higher likelihood suffering Typhoons and most of established wind farm locate in west coast of Taiwan, it is speculated that long term variation trend of wind do not have notable negative impact on wind power generation in Taiwan.

• Korean Journal of Adult Nursing
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• v.25 no.3
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• pp.298-311
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• 2013

Purpose: The purpose of this study was to compare reported physical symptoms, hope and family support of cancer patients between general hospitals and long-term care hospitals. Methods: Subjects were 175 patients diagnosed with cancers from two general hospitals and six long-term care hospitals located in G city. Subjects completed a questionnaire with questions about general characteristics and questions about the disease, physical symptoms, hope and family support. Data was collected from February to April and the data were analyzed using an independent t-test and one-way ANOVA. Results: The subjects in long-term care hospitals showed higher percentage in pain, nausea, fatigue, sleep disorder, and change in appearance. There was a significant difference in family support between two groups. A significant positive correlation was found between hope and family support in subjects in general and long-term care hospitals. Conclusion: Significant differences were found in some physical symptoms and family support between cancer patients in general hospitals and long-term care hospitals. Thus, nurses in long-term care hospitals need provide care suitable for the characteristics of cancer patients in long-term care hospitals.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.264-271
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• 2023

Environmental crises caused by climate change and human-induced disturbances have become urgent challenges to the sustainability of human beings. These issues can be addressed based on a data-driven understanding and forecasting of ecosystem responses to environmental changes. In this study, we introduce a long-term ecological monitoring system in Korean Long-Term Ecological Research (KLTER), and a plan for the Korean Ecological Observatory Network (KEON). KLTER has been conducted since 2004 and has yielded valuable scientific results. However, the KLTER approach has limitations in data integration and coordinated observations. To overcome these limitations, we developed a KEON plan focused on multidisciplinary monitoring of the physiochemical, meteorological, and biological components of ecosystems to deepen process-based understanding of ecosystem functions and detect changes. KEON aims to answer nationwide and long-term ecological questions by using a standardized monitoring approach. We are preparing three types of observatories: two supersites depending on the climate-vegetation zones, three local sites depending on the ecosystem types, and two mobile deployment platforms to act on urgent ecological issues. The main observation topics were species diversity, population dynamics, biogeochemistry (carbon, methane, and water cycles), phenology, and remote sensing. We believe that KEON can address environmental challenges and play an important role in ecological observations through partnerships with international observatories.

• Journal of The Geomorphological Association of Korea
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• v.20 no.1
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• pp.75-83
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• 2013

Human-induced modifications in coastal area may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. Morever, engineering structure have been built to stabilize coastal change, these effort impact on other morphologic change. In case of coastal area, there are lack of sediment yield data. This study focus on the tendency of long-term shoreline change, estimate method od sediment discharge which is a major factor of coastal change and adduced to way for considering design load influenced to coastal road.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.398-403
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• 1993

A rule based fuzzy expert system to self-tune PID controllers is proposed in this paper. The proposed expert system contains two rule bases, where one is responsible for "Long term tuning" and the other for "Incremental tuning". The rule for "Long term tuning" are extracted from the Wills'map and the knowledge about the implicit relations between PID gains and important long term features of the output response such as overshoot, damping and rise time, etc., while 'Incremental tuning" rules are obtained from the relations between PID gains and short term features, error and change in error. In the PID control environment, the proposed expert system operates in two phases sequentially. In the first phase, the long term tuning is performed until long term features meet their desired values approximately. Then the incremental tuning tarts with PID gains provided by the long term tuning procedure. It is noticeable that the final PID gains obtained in the incremental tuning phase are only the temporal ones. Simulation results show that the proposed rule base for "Long term tuning" provides superior control performance to that of Litt and that further improvement of control performance is obtained by the "Incremental tuning'.ance is obtained by the "Incremental tuning'.ing'.

• Journal of Environmental Policy
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• v.5 no.3
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• pp.57-78
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• 2006

Now post 2012 greenhouse gas reduction commitment being discussed, studies about long-term GHG reduction scenarios toward 2050 have actively been worked separately from 5 years short-term approach. In this paper, background, temperature target, $CO_2$ concentration target, national emission target, and approach of long-term reduction scenarios toward 2050 particularly in European countries such as UK, Germany, France, Netherlands et al. are reviewed. After comparing GDP and emission indices between Developed (European) countries and Korea, some implications of long-term GHG reduction scenarios are deduced. Acting early owing to uncertainty in climate change impact and technology development rather than delaying reduction activity owing to scientific uncertainty in climate change is needed. Providing our society's vision of climate change and government's explicit direction through long-term GHG reduction target setting toward 2050 and economic units' preparing for those are needed.