• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.61-71
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• 2018

Purpose: Research on the clinical role of Staphylococcus aureus as a pathogen in acute gastroenteritis (AGE) in children has been scarce. This study aimed to clarify the prevalence and clinical correlation of S. aureus detection in children with AGE. Methods: Fecal samples were collected from children with symptoms of AGE who visited a secondary hospital between January 2012 and December 2015. The samples were sent to the Seoul Metropolitan Government Research Institute of Public Health and Environment to test for pathogenic organisms. Clinical patterns were analyzed through medical record review. Results: Among the 663 participants, the bacteria detection rate was 26.2% (n=174), the virus detection rate was 29.7% (n=197), and the non-detection rate was 43.1% (n=286). S. aureus was tested positive from 102 cases and was confirmed as a single pathogen in 53 cases. It was the third most common pathogen. The prevalence by age was highest (45.3%) in 0-2 year-olds. Most cases occurred in summer. Symptoms included diarrhea (71.7%), vomiting (67.9%), fever (49.1%), and abdominal pain (37.7%). Only vomiting showed a significant difference between the S. aureus group and the non-detection group (67.9% vs. 43.0%; P=0.001). Among enterotoxins, the higher incidence of vomiting was associated with classical staphylococcal enterotoxins (SEA, SEB, SEC, SED, and SEE) and SEH (P=0.027). Conclusions: S. aureus was the bacteria commonly isolated from children with AGE. Our study identified cases of staphylococcal AGE in children based on fecal samples and confirmed the characteristic symptoms, affected age groups, seasonal distribution, and correlation with enterotoxins.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.166-173
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• 1983

To investigate the varietal differences of weed competitive functions under the three different seasons of transplanting, rice cultivars Milyang 23 and Sadominori were used with seven weeding methods, namely, weedy check, weed-free, once weeding at 3, 6, 9, 12 weeks after transplanting, and two times weeding at 3 and 9 weeks after transplanting, respectively. As a result, weeding stages and times for the proper weeding efficacies and reasonable rice productivities by respective weed group and total weed flora were estimated. Also, the constructive characteristics for yield formations under the different competitive conditions as affected by various cropping patterns were discussed.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.115-131
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• 1996

Tourism is multi-faceted phenomenon which involves movement to stay in destinations outside the normal place of residence. Thus, tourism is a composite phenomenon which incorporates the diversity of variables and relationships to be found in the tourist travel process. Tourism-behaviors are of major economic and social significance. With the growth of mass-tourism, the government departments of tourism is to provide many tourist facilities, to develop travel destination and tourism resources. At same time, the growth of mass-tourism has prompted perceptive travellers to raise many questions concerning the many travel destination and the tourism resources of encouraging further tourism demand. Most of tourism have a mental in their minds about various objects. This allowed him to choose tourism destination as a important rules. In tourism geography, behavioral approach to wildness, tourism resources and places has risen since 1960's. The tourist profile can be viewed under two major categories: the tourist social-economic and behavioral characteristic. Particulary, the motivations, attitude, need, values and preference of travel destinations are of crucial importance in contributing to their desion-making process. In this view, this paper is emprical study investigated travel patterns and behavioral characteristic of tourists and potential tourist in East Chonnam. The purpose of this paper is to show the spatial preference and tourism behavior of travel destinations. For this study, we are undertaken the questionary method employed by recreation geographers in order to collect research data for the East Chonnam-citizens functioned as a major tourist demand. The East Chonnam Province have many tourist-places including national park, provincial park, and local tourist-places. Thus, citizen of the East Chonnam evaluate many tourist-places very high, but evaluate the facilities of tourist place very low. The high ranks of preferences to travel destinations among tourist-places are Hyangilam, Geomoon island, Odongis land, Songkwang temple. The major travel destinations occurred the temporary travel trip are Odong island, Sunam temple, Songkwang temple. Heungkook temple, Hyangilam which are the type of mountainous in located inland. The relationship between the degree of preference and tourism behavior of travel trip for the travel destinations does not correlate each other. The result of analysis about the degree of seasonal preferences presented spatial differences according to characteristics of tourist-places. The typical travel destination are divided into seasons : Odong island. Mt. Backwoon, Goemoon island of spring, Goemoon island, Sungbul valley, Banggukpo beach of summer, Songkwang temple, Mt. Pal young of fall. The future of tourism will be rapidly grow with increase of personal mobility and leisure time, chang of tourism behavior. Thus, it is imperative that planning and development for tour-root, facilities of tourist-places should be implemented to increase tourism demand.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.298-310
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• 1997

The aim of this research was to evaluate the biotic environments based upon the community pattern of demersal fishes in the Masan bay which is heavily polluted area in the southern part of Korea. The baited traps or bottom gillnet sampled bottom fishes at four sites totally 14 tunes from March 1994 to December 1996 with 2~3 months interval. The baited trap caught 0~ 10 species which were mainly starfish, crabs, conger eel, rockfish, or blenny with 0~50 individuals per a trap. Small crab(Atergatis sp.) was significantly dominant in the S1 site, most heavily polluted area, and starfish(Asterias sp. and/or Asterina sp.) in the other three sites. There was no animals at the S1 site in the March and July in 1994 and August in 1996. The gillnets caught 0~7 species which were mainly mantis shrimp, jellyfish, flounder, starfish, crabs, or sea weeds with 0~30 individuals per a pannel of bottom gillnet. Jellyfish was significantly dominant in the S1 site and mantis shrimp in the all four sites. There was no animals in the July 1994 at S1 site and in the August and December 1996 at S4 site. But at the August in 1995 or 1996 in the S1 site, the bottom gillnets caught mackerel, anchovy, gizzard-shad or mullet which was dead all. The species diversity index of samlings by trap or gillnet showed less than 1.0 in the 80% of the totally 56 samplings. This means that the stability of demersal fishes' community is very low owing to the poor biotic environments. But most of fishes living at Masan bay appeared well fitting with the heavily polluted environments. And some fishes, like mackerel, anchovy, gizzard-shad or mullet migrated into polluted Masan bay with the seasonal or annual fluctuation.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.39-48
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• 2014

In coastal region, estuaries have complex environments where dissolved and particulate matters are mixed with marine water and substances. Suspended sediment (SS) dynamics in coastal water, in particular, plays a major role in erosion/deposition processes, biomass primary production and the transport of nutrients, micropollutants, heavy metals, etc. Temporal variation in suspended sediment concentration (SSC) can be used to explain erosion/sedimentation patterns within coastal zones. Remotely sensed data can be an efficient tool for mapping SS in coastal waters. In this study, we analyzed the variation in SSC in coastal water using the Geostationary Ocean Color Imager (GOCI) and Landsat Enhanced Thematic Mapper Plus (ETM+) in Gyeonggi-bay. Daily variations in GOCI-derived SSC showed low values during ebb time. Current velocity and water level at 9 and 10 am is 37.6, 28.65 $cm{\cdot}s^{-1}$ and -1.23, -0.61 m respectively. Water level has increased to 1.18 m at flood time. In other words, strong current velocity and increased water level affected high SSC value before flood time but SSC decreased after flood time. Also, we compared seasonal SSC with the river discharge from the Han River and the Imjin River. In summer season, river discharge showed high amount, when SSC had high value near the inland. At this time SSC in open sea had low value. In contrast, river discharge amount from inland showed low value in winter season and, consequently, SSC in the open sea had high value because of northwest monsoon.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.285-295
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• 2014

This study was conducted to survey the epidemiological characteristics and the isolated strains for pathogenic E. coli which was the major causative organisms for food poisoning occurred at school food services in the Gyeonggi-do area during the past three years. We investigated 19 accidents of food-borne disease outbreaks by pathogenic E. coli at school food services from 2010 to 2012. Food-borne disease outbreaks by pathogenic E. coli were usually occurred at direct management type (18 accidents, 95%) and high schools. For the seasonal factors, 13 accidents (65%) were occurred in June to September, especially the end of August and September after the summer holidays. The first patients were occurred on Wednesday (7 accidents, 37%) and Thursday (7 accidents, 37%), and they were mainly reported on Thursday (7 accidents, 37%) and Friday (5 accidents, 26%). The exposure of risk was estimated in Monday (4 accidents, 21%), Tuesday (7 accidents, 37%) and Wednesday (4 accidents, 21%), and kimchi (5 accidents, 50%) was estimated as the food of the high risk responsible for the outbreaks. 98 isolates of pathogenic E. coli consisted of PEC (50%), ETEC (34%), EAEC (15%), and EHEC (1%). The antibiotic resistance of pathogenic E. coli showed in the descending order of ampicilline (40%), nalidixic acid (37%), trimethoprim/sulfamethoxazole (24%), and tetracycline (19%). The antibiotics of second and third generation cephalosporins, cabarpenem, aminoglycosides, and second generation quinolones had antimicrobial susceptibilities and cefalotin, ampicillin/sulbactam and chloramphenicol showed medium resistance at 29%, 25%, and 6% respectively, and 70% of isolates were resistant to more than one antibiotic. By the PFGE analysis, they were classified into nine major groups and 31 profiles with 57% pattern similarity. It was very difficult to find the correlation of antimicrobial susceptibilities and genotype in the small scale-food poisoning, but the similarity of antimicrobial resistance and PFGE patterns in the large scale-food poisoning enabled the outbreaks to estimate the same pathotype of E. coli derived from identical origins.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1739-1756
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• 2021

Atmospheric nitrogen dioxide (NO₂) is mainly caused by anthropogenic emissions. It contributes to the formation of secondary pollutants and ozone through chemical reactions, and adversely affects human health. Although ground stations to monitor NO₂ concentrations in real time are operated in Korea, they have a limitation that it is difficult to analyze the spatial distribution of NO₂ concentrations, especially over the areas with no stations. Therefore, this study conducted a comparative experiment of spatial interpolation of NO₂ concentrations based on two linear-regression methods(i.e., multi linear regression (MLR), and regression kriging (RK)), and two machine learning approaches (i.e., random forest (RF), and support vector regression (SVR)) for the year of 2020. Four approaches were compared using leave-one-out-cross validation (LOOCV). The daily LOOCV results showed that MLR, RK, and SVR produced the average daily index of agreement (IOA) of 0.57, which was higher than that of RF (0.50). The average daily normalized root mean square error of RK was 0.9483%, which was slightly lower than those of the other models. MLR, RK and SVR showed similar seasonal distribution patterns, and the dynamic range of the resultant NO₂ concentrations from these three models was similar while that from RF was relatively small. The multivariate linear regression approaches are expected to be a promising method for spatial interpolation of ground-level NO₂ concentrations and other parameters in urban areas.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.664-674
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• 2021

The relevance of this scientific research is determined by the negative impact of the COVID-19 pandemic on the current trends and dynamics of world tourism development. This article aims to identify patterns of development of the modern tourist market, analysis of problems and prospects of development in the context of the COVID-19 pandemic. Materials and methods. General scientific methods and methods of research are used in the work: analysis, synthesis, comparison, analysis of statistical data. The analysis of the viewpoints of foreign and domestic authors on the research of the international tourist market allowed us to substantiate the actual directions of tourism development due to the influence of negative factors connected with the spread of a new coronavirus infection COVID-19. Economic-statistical, abstract-logical, and economic-mathematical methods of research were used during the process of study and data processing. Results. The analysis of the current state of the tourist market by world regions was carried out. It was found that tourism is one of the most affected sectors from COVID-19, as, by the end of 2020, the total number of tourist arrivals in the world decreased by 74% compared to the same period in 2019. The consequence of this decline was a loss of total global tourism revenues by the end of 2020, which equaled $1.3 trillion. 27% of all destinations are completely closed to international tourism. At the end of 2020, the economy of international tourism has shrunk by about 80%. In 2020 the world traveled 98 million fewer people (-83%) relative to the same period last year. Tourism was hit hardest by the pandemic in the Asia-Pacific region, where travel restrictions are as strict as possible. International arrivals in this region fell by 84% (300 million). The Middle East and Africa recorded declines of 75 and 70 percent. Despite a small and short-lived recovery in the summer of 2020, Europe lost 71% of the tourist flow, with the European continent recording the largest drop in absolute terms compared with 2019, 500 million. In North and South America, foreign arrivals declined. It is revealed that a significant decrease in tourist flows leads to a massive loss of jobs, a sharp decline in foreign exchange earnings and taxes, which limits the ability of states to support the tourism industry. Three possible scenarios of exit of the tourist industry from the crisis, reflecting the most probable changes of monthly tourist flows, are considered. The characteristics of respondents from Ukraine, Germany, and the USA and their attitude to travel depending on gender, age, education level, professional status, and monthly income are presented. About 57% of respondents from Ukraine, Poland, and the United States were planning a tourist trip in 2021. Note that people with higher or secondary education were more willing to plan such a trip. The results of the empirical study confirm that interest in domestic tourism has increased significantly in 2021. The regression model of dependence of the number of domestic tourist trips on the example of Ukraine with time tendency (t) and seasonal variations (Turˆt = 7288,498 - 20,58t - 410,88∑5) it forecast for 2020, which allows stabilizing the process of tourist trips after the pandemic to use this model to forecast for any country. Discussion. We should emphasize the seriousness of the COVID-19 pandemic and the fact that many experts and scientists believe in the long-term recovery of the tourism industry. In our opinion, the governments of the countries need to refocus on domestic tourism and deal with infrastructure development, search for new niches, formats, formation of new package deals in new - domestic - segment (new products' development (tourist routes, exhibitions, sightseeing programs, special rehabilitation programs after COVID) -19 in sanatoriums, etc.); creation of individual offers for different target audiences). Conclusions. Thus, the identified trends are associated with a decrease in the number of tourist flows, the negative impact of the pandemic on employment and income from tourism activities. International tourism needs two to four years before it returns to the level of 2019.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.105-117
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• 2019

In order to investigate the characteristics of benthic macroinvertebrate communities in the Gihwa stream, a tributary of the Dong River, we surveyed the community and environmental factors in April and November 2013 at 6 sites. The benthic macroinvertebrate taxa represented total 63 species belonging to 29 families, 12 orders, 5 classes and 4 phyla. Total 48 (10~28 in each site) species were collected in April and 44 (13~24 in each site) in November. The number of individuals increased slightly from $560{\sim}2,290m^{-2}$ in April to $806{\sim}3,674m^{-2}$ in November. Chironomidae spp. was dominant species in April and Stenopsyche bergeri was dominant species in November. In the Functional Feeding Groups, Gathering-collector(53.9%) was dominant in April, while Filtering-collector (44.3%) increased in November. Intolerant order category (i.e. EPT species richness) in St.1, St.5 and St.6 increased in November compared to April due to the increase of Trichoptera. St.2, St.3 and St.4, which were located near the fish farm, were low EPT as a whole, but Benthic macroinvertebrate index (BMI) was good state in November than April due to decrease of Chironomidae spp.. The environmental factors in the survey site showed similar tendency except for St.1 between both seasons, and electrical conductivity, salinity, and water width showed seasonal differences. Cluster analysis and Nonmetric multidimensional scaling (NMDS) based on benthic macroinvertebrate community data were divided into two groups according to season. Electrical conductivity, salinity and substrate composition were the most influential factors determining the distribution patterns of macroinvertebrate communities.

• Ecology and Resilient Infrastructure
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• v.8 no.1
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• pp.32-43
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• 2021

Multichannel automated chamber systems (MCACs) were developed for the continuous monitoring of soil CO2 efflux in forest ecosystems. The MCACs mainly consisted of four modules: eight soil chambers with lids that automatically open and close, an infrared CO2 analyzer equipped with eight multichannel gas samplers, an electronic controller with time-relay circuits, and a programmable logic datalogger. To examine the stability and reliability of the developed MCACs in the field during all seasons with a high temporal resolution, as well as the effects of temperature and soil water content on soil CO2 efflux rates, we continuously measured the soil CO2 efflux rates and micrometeorological factors at the Nam-san experimental site in a Quercus mongolica forest floor using the MCACs from January to December 2010. The diurnal and seasonal variations in soil CO2 efflux rates markedly followed the patterns of changes in temperature factors. During the entire experimental period, the soil CO2 efflux rates were strongly correlated with the temperature at a soil depth of 5 cm (r2 = 0.92) but were weakly correlated with the soil water content (r2 = 0.27). The annual sensitivity of soil CO2 efflux to temperature (Q10) in this forest ranged from 2.23 to 3.0, which was in agreement with other studies on temperate deciduous forests. The annual mean soil CO2 efflux measured by the MCACs was approximately 11.1 g CO2 m-2 day-1. These results indicate that the MCACs can be used for the continuous long-term measurements of soil CO2 efflux in the field and for simultaneously determining the impacts of micrometeorological factors.