• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.18-18
• /
• 2011

Climate change is impacting and will increasingly impact both the quantity and quality of the world's water resources in a variety of ways. In some areas warming climate results in increased rainfall, surface runoff, and groundwater recharge while in others there may be declines in all of these. Water quality is described by a number of variables. Some are directly impacted by climate change. Temperature is an obvious example. Notably, increased atmospheric concentrations of $CO_2$ triggering climate change increase the $CO_2$ dissolving into water. This has manifold consequences including decreased pH and increased alkalinity, with resultant increases in dissolved concentrations of the minerals in geologic materials contacted by such water. Climate change is also expected to increase the number and intensity of extreme climate events, with related hydrologic changes. A simple framework has been developed in New Zealand for assessing and predicting climate change impacts on water resources. Assessment is largely based on trend analysis of historic data using the non-parametric Mann-Kendall method. Trend analysis requires long-term, regular monitoring data for both climate and hydrologic variables. Data quality is of primary importance and data gaps must be avoided. Quantitative prediction of climate change impacts on the quantity of water resources can be accomplished by computer modelling. This requires the serial coupling of various models. For example, regional downscaling of results from a world-wide general circulation model (GCM) can be used to forecast temperatures and precipitation for various emissions scenarios in specific catchments. Mechanistic or artificial intelligence modelling can then be used with these inputs to simulate climate change impacts over time, such as changes in streamflow, groundwater-surface water interactions, and changes in groundwater levels. The Waimea Plains catchment in New Zealand was selected for a test application of these assessment and prediction methods. This catchment is predicted to undergo relatively minor impacts due to climate change. All available climate and hydrologic databases were obtained and analyzed. These included climate (temperature, precipitation, solar radiation and sunshine hours, evapotranspiration, humidity, and cloud cover) and hydrologic (streamflow and quality and groundwater levels and quality) records. Results varied but there were indications of atmospheric temperature increasing, rainfall decreasing, streamflow decreasing, and groundwater level decreasing trends. Artificial intelligence modelling was applied to predict water usage, rainfall recharge of groundwater, and upstream flow for two regionally downscaled climate change scenarios (A1B and A2). The AI methods used were multi-layer perceptron (MLP) with extended Kalman filtering (EKF), genetic programming (GP), and a dynamic neuro-fuzzy local modelling system (DNFLMS), respectively. These were then used as inputs to a mechanistic groundwater flow-surface water interaction model (MODFLOW). A DNFLMS was also used to simulate downstream flow and groundwater levels for comparison with MODFLOW outputs. MODFLOW and DNFLMS outputs were consistent. They indicated declines in streamflow on the order of 21 to 23% for MODFLOW and DNFLMS (A1B scenario), respectively, and 27% in both cases for the A2 scenario under severe drought conditions by 2058-2059, with little if any change in groundwater levels.

• Journal of Environmental Science International
• /
• v.26 no.2
• /
• pp.133-146
• /
• 2017

This study aimed to develop strategies to re-establish the Park Nature Conservation Area in Bukhansan National Park, reflecting landscape ecological value by using the zonation program Marxan with Zones. Planning unit was set by watershed, and the basic data were mapped, considering topographical and ecological values. Mapped indicators were analyzed with the application framework of Marxan with Zones by indexing some indicators. The zones divided into Park Nature Conservation Area (Zone A), Park Nature Environment Area I(Zone B) which is reflected on the concept of Potential Park Nature Conservation Area and Park Nature Environment Area II(Zone C). The best solution for each of the scenarios was fixed through the sensitiveness analysis. From these, the final solution was selected considering five criteria including area ratio of conservation area and grouping. Lastly, the final solution was verified in the overlapped analysis with recent zonation. According to the results, the number of watersheds was 77, with an average area of $1,007,481m^2$. In terms of basic mapping and indexation, the slope index and number of landscape resources for topographical property were average 0.22 and 38 places, respectively. Biotope index was average 0.69 and legally protected species was 14 species, reflecting ecological values. As the social and economic indicators, trail index was average 0.04, and the number of tour and management facilities was 43 places. Through the framework of Marxan with Zones, the best solution for scenario 1 which was set by the highest conservation criteria was selected as the final solution, and the area ratio of Park Nature Conservation Area and grouping was excellent. As the result of overlapped analysis, suggested zonation of the Park Nature Conservation was better than the recent zonation in the area raito (28.3%), biotope grade I(15.4%) and the distribution points (10 places) of legally protected species with verification of proper distribution of conservation features according to the zone.

• Ocean and Polar Research
• /
• v.34 no.2
• /
• pp.197-199
• /
• 2012

According to the IPCC climate change scenario (A1B scenario), the surface seawater temperature of the South Sea of Korea by 2100 may be $2-3.5^{\circ}C$ higher than at present, and seawater pH may decrease from 8.1 to 7.8, due to the increase in atmospheric $CO_2$, which is predicted to increase in concentration from 380 to 750 ppm. These changes may not only intensify the strength of typhoons/storm surges but also affect the function and structure the marine ecosystem. In order to assess the impact of climate change on the marine ecosystem in Korean waters, the project named the 'Assessment of the impact of climate change on marine ecosystem in the South Sea of Korea' has been supported by the Ministry of Land, Transport and Maritime Affairs, from 2008. The goal of this project is to enhance our ability to adapt and prepare for the future environmental changes through the reliable predictions based on the knowledge obtained from projects like this. In this respect, this project is being conducted to investigate the effects of climate/marine environment changes (ocean warming and acidification), and to predict future changes of the structure and function of the ecosystem in the South Sea of Korea. This special issue contains 6 research articles, which are the highlights of the studies carried out through this project.

• Earthquakes and Structures
• /
• v.15 no.1
• /
• pp.29-44
• /
• 2018

A ground-motion prediction equation (GMPE) for the Korean Peninsula, especially for South Korea, is developed based on synthetic ground motions generated using a ground motion model derived from instrumental records from 11 recent earthquakes of $M_L$>4.5 in Korea, including the Gyeongju earthquake of Sept. 12. 2016 ($M_L$5.8). PSAs of one standard deviation from the developed GMPE with $M_W$ 6.5 at hypocentral distances of 15 km and 25 km are compared to the design spectrum (soil condition, $S_B$) of the Korean Building Code 2016 (KBC), indicating that: (1) PSAs at short periods around 0.2 sec can be 1.5 times larger than the corresponding KBC PSA, and (2) SD's at periods longer than 2 sec do not exceed 8 cm. Although this comparison of the design spectrum with those of the GMPE developed herein intends to identify the characteristics of the scenario earthquake in a lower-seismicity region such as South Korea, it does not mean that the current design spectrum should be modified accordingly. To develop a design spectrum compatible with the Korean Peninsula, more systematic research using probabilistic seismic hazard analysis is necessary in the future.

• Educational Technology International
• /
• v.7 no.1
• /
• pp.1-20
• /
• 2006

This paper describes practical research on the improvement of teaching and learning process by integrating Web Bulletin Board (WBB) and mobile phone. This paper addresses three topics; A) the interactive lecture with topics-based discussions using the Web Bulletin Board (WBB) as a tool for assisting discussion, B) the introduction of peer evaluation among students to develop their problem-solving and cognitive skills, C) the use of mobile phones for promoting interactive lectures, keeping class attendance, conducting assignments, and providing notices for the next class. Results indicated the following research-findings: (1) WBB plays a role in facilitating positive participation in classes. (2) In contrast to the scenario of the traditional mode of instruction (without the usage of WBB), students were able to deepen their understanding of the theme by accessing the WBB before and after classes. (3) Peer evaluation highly promoted students' motivation to learn, and was effective in cultivating meta-cognition through modeling. (4) Mobile phone was identified as a highly effective tool for keeping class attendance, realizing interactive classes by generating discussions, and managing assignments and homework.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.1B
• /
• pp.34-41
• /
• 2002

In this paper, the algorithms increase the capacity of the forward link channel are studied in the DS-CDMA mobile communication system with the technology of transmit antenna array. Through of the implementation of the test bed with PC and DSP boards, the hardware implementation and optimization of the algorithms, the operation scenario and architecture of the test bed, are considered. In addition, the performance analyses are achieved about the execution time of the algorithms.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.383-385
• /
• 2010

This study analyzed the change of flowout and suspend solid in Andong and Imha basin according to the climate change to develop evaluation index about turbid water occurrence possibility and to support the countermeasures for turbid water management using GIS-based Soil and Water Assessment Tools (SWAT). MIROC3.2 hires model values of A1B climate change scenario that were supplied by Intergovernmental Panel on Climate Change (IPCC) were applied to future climage change data. Precipitation and temperature were corrected by applying the output value of 20th Century Climate Coupled Model (20C3M) based on past climate data during 1977 and 2006 and downscaled with Change Factor (CF) method. And future climate change scenarios were classified as three periods (2020s, 2050s, 2080s) and the change of flowout and suspended solid according to the climate change were estimated by coupling modeled value with SWAT model.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.4
• /
• pp.39-47
• /
• 2011

The aim of the study is to predict potential evapotranspiration and crop water requirement using meteorological data from MIROC3.2 with A1B scenario. Increase of evapotranspiration due to temperature rise can be observed out of the analysis, while effective rainfall decreased. The evapotranspiration elevation results in large amount of crop water requirement in the paddy farming. It can be seen that rainfall intensification at non-irrigation period brings effective rainfall decrease, while contributes to higher demand of crop water at irrigation period. It is necessary to secure additional water resources to adapt the climate change. It is expected that estimation on potentialevapotranspiration in this study can be used for formulation of master plan of water resources.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.276-276
• /
• 2012

일반적으로 기후변화영향에 관한 연구수행을 위해 전지구기후모형(GCM; Global Climate Model)이 사용되고 있다. 하지만 GCM은 공간해상도(Spatial resolution)가 거칠기 때문에 수문학 분야에서 주로 사용되는 유역규모의 지역적인 스케일특성과 물리적 특징을 표현하는데 한계가 있다. 또한 GCM 기후변수들 중 강수량의 경우 한반도 지역의 6월과 10월 사이에 연강수량의 67% 이상이 집중되는 계절성을 반영하지 못하고 있으며, 높은 불확실성을 보이고 있다. 본 연구에서는 GCM 기반의 다지점 인공신경망기법을 적용한 상세화(Downscaling)를 실시하였다. GCM의 24개 2D변수에 대한 주성분분석을 실시하여 신경망의 학습인자로 사용하였으며, 학습, 검증 및 예측기간은 각각 1981~1995년, 1996~2000년, 2011~2100년으로 A1B 시나리오를 대상으로 상세화를 실시하였다. 또한, 여름철 태풍사상을 모의하기 위한 Stochastic Typhoon Simulation기법과 Baseline과 Projection 사이의 강수량 보정을 위한 Dynamic Quantile Mapping 기법을 적용하여, 강수량의 불확실성을 최소화 하고자 하였다.

• Molecules and Cells
• /
• v.39 no.1
• /
• pp.72-76
• /
• 2016

Cell death pathways such as apoptosis can be activated in response to oxidative stress, enabling the disposal of damaged cells. In contrast, controlled intracellular redox events are proposed to be a significant event during apoptosis signaling, regardless of the initiating stimulus. In this scenario oxidants act as second messengers, mediating the post-translational modification of specific regulatory proteins. The exact mechanism of this signaling is unclear, but increased understanding offers the potential to promote or inhibit apoptosis through modulating the redox environment of cells. Peroxiredoxins are thiol peroxidases that remove hydroperoxides, and are also emerging as important players in cellular redox signaling. This review discusses the potential role of peroxiredoxins in the regulation of apoptosis, and also their ability to act as biomarkers of redox changes during the initiation and progression of cell death.