• ALGAE
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• v.37 no.2
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• pp.123-133
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• 2022

Genetic diversity and distribution patterns of marine macroalgae are increasingly being documented in Southeast Asia. These studies show that there can be significant levels of genetic diversity and isolation between populations on either side of the Thai-Malay Peninsula. Bostrychia tenellla is a common filamentous red seaweed in the region and the entity is represented by at least two cryptic species. Despite being highly diverse and widespread, genetic variation and population structure of this species complex remains understudied, especially around the Thai-Malay Peninsula. We analyzed genetic diversity and inferred the phylogeographic pattern of specimens identified as B. tenella using the plastid RuBisCo spacer from samples from the Andaman Sea and the Gulf of Thailand. Our genetic analysis confirmed the occurrence of the two cryptic B. tenella species (B and C) along both coasts. Cryptic species B was more common in the area and displayed higher genetic diversity than species C. Historical demographic analyses indicated a stable population for species B, but more recent population expansion for species C. Our analyses also revealed that both cryptic species from the Andaman Sea possessed higher genetic diversity than those of the Gulf of Thailand. We also detected moderate to high levels of gene flow and weak phylogeographic structure of cryptic species B between the two coasts. In contrast, phylogeographic analysis showed genetic differences between populations of both cryptic species within the Andaman Sea. Overall, these results suggest that cryptic B. tenella species around Thai-Malay Peninsula may have undergone different demography histories, and their patterns of genetic diversity and phylogeography were likely caused by geological history and regional sea surface current circulation in the area.

• Journal of Preventive Medicine and Public Health
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• v.55 no.2
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• pp.134-143
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• 2022

Objectives: Many governments have imposed-and are still imposing-mobility restrictions to contain the coronavirus disease 2019 (COVID-19) pandemic. However, there is no consensus on whether policy-induced reductions of human mobility effectively reduce the effective reproduction number (Rt) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several studies based on country-restricted data reported conflicting trends in the change of the SARS-CoV-2 Rt following mobility restrictions. The objective of this study was to examine, at the global scale, the existence of regional specificities in the correlations between Rt and human mobility. Methods: We computed the Rt of SARS-CoV-2 using data on worldwide infection cases reported by the Johns Hopkins University, and analyzed the correlation between Rt and mobility indicators from the Google COVID-19 Community Mobility Reports in 125 countries, as well as states/regions within the United States, using the Pearson correlation test, linear modeling, and quadratic modeling. Results: The correlation analysis identified countries where Rt negatively correlated with residential mobility, as expected by policymakers, but also countries where Rt positively correlated with residential mobility and countries with more complex correlation patterns. The correlations between Rt and residential mobility were non-linear in many countries, indicating an optimal level above which increasing residential mobility is counterproductive. Conclusions: Our results indicate that, in order to effectively reduce viral circulation, mobility restriction measures must be tailored by region, considering local cultural determinants and social behaviors. We believe that our results have the potential to guide differential refinement of mobility restriction policies at a country/regional resolution.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.3
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• pp.110-114
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• 2010

A data set of current, wind and wave height measured at the monitoring buoy and sea level at Busan harbor were analyzed to explain the physical conditions during the strong rip current events at Haeundae Beach of Suyeong Bay during 13~15 August 2009. Tidal current, with spring-neap variations, has similar average speed to the short-term non-tidal currents. The common features at the time of rip currents are the strong northeasterly wind and superposition of tidal and non-tidal currents both flowing toward the coast. However on 14 August when the rip current did not occur, tide and wave height were similar to the rip-current cases but the tidal and non-tidal current were to nearly opposite directions. While strong winds produce large waves thus the basic condition for rip current but its influence on the local circulation in the bay is relatively small. Of the three adjacent beaches, only at Haeundae the rip currents are reported. This difference may be due to the unique bottom topography featured by underwater hill in the central region off Haeundae which can decay the incoming waves, tides and currents to intensify the rip current.

• Korean Circulation Journal
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• v.53 no.2
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• pp.69-91
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• 2023

Cardio-oncology is an emerging multi-disciplinary field, which aims to reduce morbidity and mortality of cancer patients by preventing and managing cancer treatment-related cardiovascular toxicities. With the exponential growth in cancer and cardiovascular diseases in Asia, there is an emerging need for cardio-oncology awareness among physicians and country-specific cardio-oncology initiatives. In this state-of-the-art review, we sought to describe the burden of cancer and cardiovascular disease in Asia, a region with rich cultural and socio-economic diversity. From describing the uniqueness and challenges (such as socio-economic disparity, ethnical and racial diversity, and limited training opportunities) in establishing cardio-oncology in Asia, and outlining ways to overcome any barriers, this article aims to help advance the field of cardio-oncology in Asia.

• Korean Circulation Journal
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• v.52 no.11
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• pp.829-843
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• 2022

Background and Objectives: Despite remarkable reduction in cardiovascular disease (CVD) mortality, the burden has remained the leading cause of death. Since little research has focused on regional disparity in CVD mortality, this study aims to investigate its spatiotemporal trends in Korea from 1983 to 2019. Methods: Using the causes of death statistics in Korea, we analyzed the geographic variation in deaths from CVDs from 1983 to 2019. The sex and age-standardized mortality rate was calculated according to the 17 administrative regions. The analyses include all diseases of the circulatory system (International Classification of Diseases-10 codes, I00-I99), along with the following 6 subcategories which were not mutually exclusive: total heart disease (I00-I13 and I20-I51), hypertensive heart disease (I10-I13), ischemic heart disease (I20-I25), myocardial infarction (I21-I23), heart failure (I50), and cerebrovascular disease (I60-I69). Results: Overall, heart failure death rate increased across all regions, and other CVD death rates showed a decreasing trend. Regional disparity in mortality was substantial in the early 1980s but converged over time. In all types of cardiovascular mortality, Busan, Ulsan and Gyeongnam remained the highest, although they showed a downward trend like other regions. Jeju continued to have a relatively low CVD mortality rate. Conclusions: The regional disparity substantially decreased compared to the 1980s. However, the relatively high burden of CVD mortality in the southeastern region has not been fully resolved.

• Atmosphere
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• v.28 no.3
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• pp.305-315
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• 2018

This study investigates the characteristic spatial patterns and dynamic processes associated with the summertime extreme temperature events in South Korea during the last 20 years (1995~2014) using Self-Organizing Map (SOM). The classified SOM patterns commonly have high temperature and anticyclonic circulation anomalies over South Korea. The two major teleconnection patterns are identified: one is from the subtropical western North Pacific (WNP) affecting to the north and the other is from the North Atlantic (NA) affecting downstream region. The meridional teleconnection pattern is related to the forcing of positive sea surface temperature (SST) anomaly over the WNP. The northward propagating Rossby wave generates the East Asia-Pacific (EAP) pattern to form an anticyclonic circulation anomaly over South Korea. On the other hand, NA SST anomalies generate an eastward Rossby wave train across the Eurasian continent, leading to the development of an anticyclonic circulation anomaly over South Korea. The EAP pattern occurs more frequently in July and August, whereas the midlatitude teleconnection pattern associated with NA SST anomalies develops more frequently in early summer (June).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.208-225
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• 2019

To understand the mean surface circulation and surface currents in the East Sea, trajectories of surface drifters passed through the East Sea from 1991 to 2017 were analyzed. By analyzing the surface drifter trajectory data, the main paths of surface ocean currents were grouped and the variation in each main current path was investigated. The East Korea Warm Current (EKWC) heading northward separates from the coast at $36{\sim}38^{\circ}N$ and flows to the northeast until $131^{\circ}E$. In the middle (from $131^{\circ}E$ to $137^{\circ}E$) of the East Sea, the average latitude of the currents flowing eastward ranges from 36 to $40^{\circ}N$ and the currents meander with large amplitude. When the average latitude of the surface drifter paths was in the north (south) of $37.5^{\circ}N$, the meandering amplitude was about 50 (100) km. The most frequent route of surface drifters in the middle of the East Sea was the path along $37.5-38.5^{\circ}N$. The surface drifters, which were deployed off the coast of Vladivostok in the north of the East Sea, moved to the southwest along the coast and were separated from the coast to flow southeastward along the cyclonic circulation around the Japan Basin. And, then, the drifters moved to the east along $39-40^{\circ}N$. The mean surface current vector and mean speed were calculated in each lattice with $0.25^{\circ}$ grid spacing using the velocity data of surface drifters which passed through each lattice. The current variance ellipses were calculated with $0.5^{\circ}$ grid spacing. Because the path of the EKWC changes every year in the western part of the Ulleung Basin and the current paths in the Yamato Basin keep changing with many eddies, the current variance ellipses are relatively large in these region. We present a schematic map of the East Sea surface current based on the surface drifter data. The significance of this study is that the surface ocean circulation of the East Sea, which has been mainly studied by numerical model simulations and the sea surface height data obtained from satellite altimeters, was analyzed based on in-situ Lagrangian observational current data.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.2
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• pp.49-57
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• 2016

Even if an external forcing that will drive a climate change is given uniformly over the globe, the corresponding climate change and the feedbacks by the climate system differ by region. Thus the detection of global warming signal has been made on a regional scale as well as on a global average against the internal variabilities and other noises involved in the climate change. The purpose of this study is to estimate a timing of unprecedented climate due to global warming and to analyze the regional differences in the estimated results. For this purpose, unlike previous studies that used climate simulation data, we used an observational dataset to estimate a magnitude of internal variability and a future temperature change. We calculated a linear trend in surface temperature using a historical temperature record from 1880 to 2014 and a magnitude of internal variability as the largest temperature displacement from the linear trend. A timing of unprecedented climate was defined as the first year when a predicted minimum temperature exceeds the maximum temperature record in a historical data and remains as such since then. Presumed that the linear trend and the maximum displacement will be maintained in the future, an unprecedented climate over the land would come within 200 years from now in the western area of Africa, the low latitudes including India and the southern part of Arabian Peninsula in Eurasia, the high latitudes including Greenland and the mid-western part of Canada in North America, the low latitudes including Amazon in South America, the areas surrounding the Ross Sea in Antarctica, and parts of East Asia including Korean Peninsula. On the other hand, an unprecedented climate would come later after 400 years in the high latitudes of Eurasia including the northern Europe, the middle and southern parts of North America including the U.S.A. and Mexico. For the ocean, an unprecedented climate would come within 200 years over the Indian Ocean, the middle latitudes of the North Atlantic and the South Atlantic, parts of the Southern Ocean, the Antarctic Ross Sea, and parts of the Arctic Sea. In the meantime, an unprecedented climate would come even after thousands of years over some other regions of ocean including the eastern tropical Pacific and the North Pacific middle latitudes where an internal variability is large. In summary, spatial pattern in timing of unprecedented climate are different for each continent. For the ocean, it is highly affected by large internal variability except for the high-latitude regions with a significant warming trend. As such, a timing of an unprecedented climate would not be uniform over the globe but considerably different by region. Our results suggest that it is necessary to consider an internal variability as well as a regional warming rate when planning a climate change mitigation and adaption policy.

• Journal of Climate Change Research
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• v.3 no.1
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• pp.71-88
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• 2012

The global warming is probably the most significant issue of concern all over the world and according to the report published by the Intergovernmental Panel on Climate Change (IPCC), the average temperature and extent of global warming around the globe have been on the rise and so have the uncertainty for the future. Such effects of global warming have adverse effects on basic foundation of the mankind in numerous ways and water resource is no exception. The researches on water resources assessment for climate change are significant enough to be used as the preliminary data for researches in other fields. In this research, a total of 124 peer-reviewed publications and 57 reports on the subject of research on climate change related to water resources, that has been carried out so far in Korea has been reviewed. The research on climate change in Korea (inclusive of the peer-reviewed articles and reports) has mainly focused on the future projection and assessment. In the fields of hydrometeorology tendency and projection, the analysis has been carried out with focus on surface water, flood, etc. for hydrological variables and precipitation, temperature, etc. for meteorological variables. This can be attributed to the large, seasonal deviation in the amount of rainfall and the difficulty of water resources management, which is why, the analysis and research have been carried out with focus on those variables such as precipitation, temperature, surface water, flood, etc. which are directly related to water resources. The future projection of water resources in Korea may differ from region to region; however, variables such as precipitation, temperature, surface water, etc. have shown a tendency for increase; especially, it has been shown that whereas the number of casualties due to flood or drought decreases, property damage has been shown to increase. Despite the fact that the intensity of rainfall, temperature, and discharge amount are anticipated to rise, appropriate measures to address such vulnerabilities in water resources or management of drainage area of future water resources have not been implemented as yet. Moreover, it has been found that the research results on climate change that have been carried out by different bodies in Korea diverge significantly, which goes to show that many inherent uncertainties exist in the various stage of researches. Regarding the strategy in response to climate change, the voluntary response by an individual or a corporate entity has been found to be inadequate owing to the low level of awareness by the citizens and the weak social infrastructure for responding to climate change. Further, legal or systematic measures such as the governmental campaign on the awareness of climate change or the policy to offer incentives for voluntary reduction of greenhouse gas emissions have been found to be insufficient. Lastly, there has been no case of any research whatsoever on the anticipated effects on the economy brought about by climate change, however, there are a few cases of on-going researches. In order to establish the strategy to prepare for and respond to the anticipated lack of water resources resulting from climate change, there is no doubt that a standardized analysis on the effects on the economy should be carried out first and foremost.

• Journal of Environmental Policy
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• v.12 no.1
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• pp.37-58
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• 2013

In recently, the low impact development(LID) is discussed at various fields being related to urban stormwater, non-point source pollution, and quality of life. It is understood as an integrated development tool to induce sustainable development with various value-social, economic, and aesthetic. As concerning the development of waterfront area, the low impact development is interested in environmental planning. But the planning process and factors are not considered in precedent research. This study has two purposes. The one is to understand the planning process and factors of low impact development from literature review. The other is to apply the planning factors using case study and to know the effect of low impact development as the simulation plan. The simulation plan is based on some landuse planning. It is divided into the setting the region for environmental protection and the function of public facilities, spatial planning for enlarging permeable area, and spatial planning for circulation of water. The simulation model uses the LIDMOD2. The 14 planning factors of low impact development is applied to case region. And the effect is about 7~10 percent in reduction of nonpoint source pollution and surface runoff.