Central Region Of South Korea Research Articles

Nitrous Oxide Emissions during Cultivation and Fallow Periods from Rice Paddy Soil under Urea Fertilization

Rice cultivation serves as a significant anthropogenic source of methane (CH4) and nitrous oxide (N2O). Although N2O emissions remain relatively small compared to CH4 emissions, they are remarkably affected by nitrogen-fertilized soil conditions during rice cultivation. While numerous studies have investigated nitrous oxide emissions in response to nitrogen fertilization, existing research assessing nitrous oxide emissions based on nitrogen fertilizer levels has often been limited to cultivation periods. Therefore, there is a need for comprehensive analyses covering the entire year, including the dry periods, to address nitrous oxide emissions as an important source throughout the entire agricultural cycle. In this case study, we investigated the characteristics of N2O emissions in a central region of South Korea, where a single rice-cropping cycle occurs annually over a span of three whole years, from May 2020 to May 2023. We investigated the impact of variations in temperature and soil moisture on N2O emissions during rice cultivation and fallow periods. In this context, we attempted to discover the complex dynamics of N2O emissions by comparing longer fallow periods with the rice cultivation periods and extended non-dry periods with irrigated periods. We discovered that the greater contribution of cumulative N2O emissions during the fallow period made a much greater contribution (up to approximately 90%) to the whole-year N2O emissions than those during the rice cultivation period. During the fallow period from rice harvest to rice planting in the following year, variations in N2O emissions were associated with high-flux events after rainy periods on dry soils. This highlights the considerable influence of soil moisture content and weather conditions on N2O emissions during the fallow period. This affects high emission events, which in turn significantly impact the cumulative emissions over the entire period. We underscore that assessing N2O emissions solely based on the rice cultivation period would underestimate annual emissions. To prevent underestimation of N2O emissions, periodic gas collection throughout a year covering both rice cultivation and fallow phases is required in alignment with the monitoring of different temperature and soil moisture conditions. We captured statistical differences in cumulative N2O emissions due to nitrogen fertilization treatments across the three years. However, no significant difference was observed in the three-year average emissions among the different (one, one-and-a-half, and double) nitrogen fertilization treatments, with the exception of the control treatment (no fertilization). Based on the findings, we recommend at least three whole-year evaluations to ensure the estimation accuracy of N2O emissions under different nitrogen fertilization conditions. The findings from this study could help prepare the further revision or refinement of N2O emission factors from rice cultivation in the national greenhouse gas inventories defined by the inter-governmental panel on climate change (IPCC).

Vegetation Changes and Yields of Tall Fescue-based Mixture Pasture in the Central Region of South Korea

Vegetation Changes and Yields of Tall Fescue-based Mixture Pasture in the Central Region of South Korea

The Lived Experiences of Non-face-to-face Psychiatric Nursing Practice among Nursing Students: A Parse research Method study

This study is a qualitative study to clarify meaning and structure of lived experiences of non-face-to-face psychiatric nursing practice among nursing student by applying Parse research method. The research question was Would you tell me about your experience of non-face-to-face psychiatric nursing practice? which was examined based on Parse's research method. Participants were 10 nursing students at a community central region of South Korea. As a result, the core concept of lived experiences of non-face-to-face psychiatric nursing practice among nursing student is as follows; Expanding awareness of self and other understanding, Preparation of communication for the formation of therapeutic relationships, Perspective through exploring the meaning of nursing.

Confirming The Validity And Reliability Of The Korean Language Fear Of COVID-19 Scale In The University Context

Background: The widespread of the newly emerged infectious human disease labeled coronavirus 2019 (COVID-19) has caused a prolonged public health crisis of pandemic proportions. The emergence and severe consequences of COVID-19 heightened anxieties and concerns. The Fear of COVID-19 Scale (FCV-19S) was developed recently to specifically measure the fear sensed by an individual about COVID-19. This study aimed to establish the factor structure, reliability, and validity of the Korean version of the FCV-19S (KF-COVID-19S) in the context of a Korean university. Methods: Data were collected from 402 university students enrolled in undergraduate degree programs at a private university in the central region of South Korea. The sample was randomly bifurcated to execute exploratory factor analysis (EFA, N = 201) and confirmatory factor analysis (CFA, N = 201). Cronbach’s alpha reliability coefficient was also applied to assess consistency. Results: Both the EFA and CFA supported a two-factor model: factor 1 (somatic symptoms) and factor 2 (emotional fear) were significantly correlated. Additionally, the two-factor model exhibited a superior fit to the data compared to the unidimensional and bifactor models. Cronbach’s alpha revealed acceptable internal consistency. Conclusion: Our results suggest that the Korean version of the FCV-19S can multidimensionally assess the severity of fear of COVID-19. However, we recommend using the single FCV-19S total score for practical purposes, given the high correlation among factors, the robust reliability of the total scale, and items implying a higher order factor of the fear sensed by individuals toward COVID-19.

Evaluation of Growth Characteristics, Productivity, and Feed Value of Different 26 Alfalfa Cultivars in Central Region of South Korea

This study was conducted in Cheonan of central region in South Korea to identify alfalfa cultivars with superior adaptability to the local environment. To evaluate the growth characteristics, productivity, and feed value of 26 alfalfa cultivars, field experiments were conducted with a randomized block design (three replicates) for three years. Among the 26 alfalfa cultivars, “Natsuwakaba” showed the highest dry matter yield (DMY, 37,083 kg/ha), with a significantly higher three-year average than that of other cultivars. Furthermore, the three-year-average DMYs of “Alfalfa short” (31,044 kg/ha) and “Radar II Brand” (31,163 kg/ha) were significantly higher than those of other cultivars. In addition, differences among the feed values of the alfalfa cultivars were relatively less significant than the differences among their productivity, as the feed value was less influenced by the cultivation conditions and cultivars. Although “Jin Huang Hou” and “Certified organic” exhibited the highest feed values when cultivated in central region in South Korea, “Natsuwakaba” outperformed all cultivars in both productivity and feed value. The acid and neutral detergent fiber (ADF and NDF, respectively) contents of “Jin Huang Hou” (38.9% and 47.26%, respectively) were significantly lower than those of other cultivars. In contrast, the ADF and NDF contents of “Burgaltai” (46.52% and 55.56%, respectively) implied poor feed value upon cultivation in South Korea. The crude protein (CP) content in the alfalfa cultivars ranged from 14.95% to 19.44% during early flowering, and the highest CP content was observed for “Certified organic.” The in-vitro digestibility of alfalfa was approximately 70% for all cultivars during early flowering, indicating good digestibility of most of the cultivars.

Epithermal Precious Metal Deposits in South Korea—History and Pursuit

Abstract The gold and silver endowment of Korea has historically been well known, with records alluding to production as far back as 1122 BC. The main gold production period was from 1925 to 1943 during the Japanese occupation of Korea, with more than 1 Moz recorded in 1939. Muguk was the most productive gold mining operation, located within the central region of South Korea, with a recorded 590 koz of gold produced from 1934 to 1998 (first mined in AD 912). The majority of the historical mining operations were closed by government order in 1943 during the Second World War and never reopened. A number of small mines operated between 1971 and 1998, with limited production during a period of gold prices generally lower than at present (~25–50% of current inflation adjusted prices, apart from a four-year period 1979–83). It is likely that significant resources remain within these historical mining areas. Gold-silver deposit types historically recognized and exploited in Korea include placers and orogenic and intrusion-related vein systems. Only more recently have epithermal vein and breccia systems been recognized. This is not surprising, given that the geologic and tectonic setting of the Southern Korean peninsula is prospective for epithermal precious metal deposits, spatially associated with basin-scale brittle fault systems in Cretaceous volcanic terranes. South Korea is an underexplored jurisdiction, with limited modern exploration and drilling until the mid-1990s, when Ivanhoe Mines Ltd. discovered the Gasado, Eunsan, and Moisan epithermal gold-silver deposits, all of which became mines. Exploration was limited for another 20 years until Southern Gold Ltd., an Australian Securities Exchange (ASX)-listed company, commenced regional-scale exploration for epithermal deposits, using a strategy similar to that successfully employed by Ivanhoe.

An artificial neural network model to predict debris-flow volumes caused by extreme rainfall in the central region of South Korea

In South Korea, the risk of debris-flow is relatively high due to the country's vast mountainous topographical features and intense continuous rainfall during the summer. Debris-flows can result in the loss of human life and severe property damage, which can be made worse due to the poor spatiotemporal predictability of such hazards. Therefore, it is essential to research the preemptive prediction and mitigation of debris-flow hazards. For this purpose, this study developed an ANN model to predict the debris-flow volume based on 63 historical events. By considering the morphology, rainfall, and geology characteristics of the studied area in central South Korea, the data of 15 debris-flow predisposing factors were obtained. Among these data, four predisposing factors (watershed area, channel length, watershed relief, and rainfall data) were selected based on Pearson's correlation analysis to check for significant correlations with the debris-flow volume. To determine the best performing ANN model, a validation testing was carried out involving ten-fold cross-validation with MSE and R2 using both training and validation datasets, which were randomly split into a 7:3 ratio. The model performance validation results showed that an ANN model with two hidden neurons (4×2×1 architecture) had the highest R2 value (0.828) and the lowest MSE (0.022). In addition, in a comparative study with other existing regression models, the ANN model showed better results in terms of adjusted R2 value (0.911) using all datasets. Furthermore, 94% of the observed debris-flow volumes from the ANN model were within 1:2 and 2:1 lines of the predicted volumes. The results of this study have shown the potentiality of the developed ANN model to be a useful resource for decision-making and designing barriers in areas prone to debris-flows in South Korea.

Effects of Seeding Date and Cultivars on Yield and Growth Characteristics of Sorghum × Sudangrass Hybrid [Sorghum bicolor (L.) Moench] Cultivars in Central Region of South Korea

Effects of Seeding Date and Cultivars on Yield and Growth Characteristics of Sorghum × Sudangrass Hybrid [Sorghum bicolor (L.) Moench] Cultivars in Central Region of South Korea

The relationship among meteorological, agricultural, and in situ news-generated big data on droughts

The purpose of this study is to evaluate the effectiveness of agricultural drought risk management using news media data (NMD) by elucidating the relationships among the standardized precipitation index (SPI), the agricultural reservoir storage deficit index (RDI), and the NMD obtained from news sources. For a severe drought that occurred in South Korea from 2014 to 2016, the SPI and RDI were calculated, and the NMD were collected. In drought-affected areas, the receiver operating characteristic (ROC) was used to assess the performance of NMD and to replicate the temporal drought trends using the SPI and RDI. The ROC analysis of NMD and drought indices showed a hit rate above 0.65, and the hit rate showed the highest value (0.75) in SPI-12. The central region of South Korea showed the highest number of news postings during the 12 months in which SPI-12 remained in the severe drought category. For the southern region of South Korea, large amounts of NMD were collected when the RDI had the lowest value. The amount of NMD was sensitive to spring drought from March, the delayed Jangma in late June, the dry Jangma in July, and the absence of a typhoon in September of 2015. The study results showed that NMD are closely related to both meteorological drought and agricultural drought conditions. As NMD represent the in situ drought experienced by the people, these data can provide a useful drought indicator along with government-published drought information.

Occurrence rates of wild rodent hosts and chigger mites and the infection rate of Orientia tsutsugamushi in the central region of South Korea from 2015 to 2018

AbstractOutbreaks of vector‐borne diseases are dramatically increasing because of climate change, consequently increasing the importance of surveillance of endemic disease vectors. In this study, we surveyed chigger mites, vectors for Orientia tsutsugamushi—the bacteria that causes Tsutsugamushi disease—, and their rodent hosts in Gimcheon, central South Korea, in 2015–2018. A total of 225 rodents were collected, with trap rate and percentage of rodents infected by chigger mites of 9.8 and 72.4%, respectively. Six species of rodents from five genera were collected, the most common rodent being Apodemus agrarius (n = 153, infection rate = 90.8%). The highest number of rodents was collected in spring (trap rate = 10.3), but the rate of infected rodents was higher in fall (81.5%) than in spring (61.3%). Trap rate was highest for bank near waterway (17.9), but the chigger index (CI) was highest in hill (224.1). A total of 20,534 (CI 126.0) chigger mite individuals from 10 species and three genera were found on the collected rodents. The most common species was Leptotrombidium pallidum (n = 7,982, 83.6%, CI 49.0), followed by L. palpale and L. scutellare. Chigger mites were most frequent at banks near waterway (n = 11,093, CI 152.0) and hill (n = 2,017, CI 224.1). To detect O. tsutsugamushi in chigger mites, 450 pools of chigger mites (n = 10,991) were analyzed; 24 pools were positive—23 of A. agrarius, the most frequently collected species in South Korea, 1 of Micromys minutus—and the minimum positive rate (MPR) was 0.22. The detected strain types included Boryong (dominant in all years, seasons, and habitats), Jecheon, 07–489, and IIOC1202.

Taxonomic review of the predatory genus Cryptalaus Ôhira (Coleoptera: Elateridae) from Korea with a new record of C. yamato (Nakane)

We studied the taxonomy of the predatory genus Cryptalaus Ôhira (Coleoptera: Elateridae) in South Korea, including two species, C. berus (Candèze) and C. larvatus pini (Lewis), which have been previously reported from South Korea. In the present study, a rare species, C. yamato (Nakane), which had been regarded as endemic to Japan, is discovered in the central region of South Korea for the first time with a DNA barcode (COI) sequence. A key, redescription, distribution map of three Korean species in Asia, and illustrations of the diagnostic characters of the Korean Cryptalaus species are provided.

Debris flow susceptibility assessment based on an empirical approach in the central region of South Korea

Many debris flow spreading analyses have been conducted during recent decades to prevent damage from debris flows. An empirical approach that has been used in various studies on debris flow spreading has advantages such as simple data acquisition and good applicability for large areas. In this study, a GIS-based empirical model that was developed at the University of Lausanne (Switzerland) is used to assess the debris flow susceptibility. Study sites are classified based on the types of soil texture or geological conditions, which can indirectly consider geotechnical or rheological properties, to supplement the weaknesses of Flow-R which neglects local controlling factors. The mean travel angle for each classification is calculated from a debris flow inventory map. The debris flow susceptibility is assessed based on changes in the flow-direction algorithm, an inertial function with a 5-m DEM resolution. A simplified friction-limited model was applied to the runout distance analysis by using the appropriate travel angle for the corresponding classification with a velocity limit of 28 m/s. The most appropriate algorithm combinations that derived the highest average of efficiency and sensitivity for each classification are finally determined by applying a confusion matrix with the efficiency and the sensitivity to the results of the susceptibility assessment. The proposed schemes can be useful for debris flow susceptibility assessment in both the study area and the central region of Korea, which has similar environmental factors such as geological conditions, topography and rainfall characteristics to the study area.

Stem taper equation analysis for Larix kaempferi species in the Central Region of South Korea

ABSTRACTTaper equation was developed to predict diameters at specific height for Larix kaempferi species in the Central Region of South Korea. The sampled trees that were collected through destructive sampling ranged from 0.60 to 47.90 cm DBH with total height ranging from 2.00 to 33.00 m. The dataset was randomly split into two: 80% for initial model fitting and 20% for model validation. The combined that means 100% dataset was used for final model fitting. Statistics of fit were used as criteria, including the coefficient of determination (R2), standard error of the estimate (SEE), bias (Ē), the absolute mean difference (AMD), and the Akaike information criterion (AIC) values and weight (AICw), with a rank analysis being applied. Initial model fitting utilized a total of nine taper equations, with the three segmented taper equations and another three non-segmented determined for model validation and final model fitting. Kozak02 equation, which had not yet been evaluated for L. kaempferi species, indicated the best performance for the species in the Central Region of South Korea. Upon comparison, the ability of this study to predict diameters at specific height and stem volume was better than the existing taper equation for L. kaempferi in South Korea.

Comparative Analysis of Simple Volume Models for Japanese Larch(Larix kaempferi) Species in the Central Region of South Korea

Comparative Analysis of Simple Volume Models for Japanese Larch(Larix kaempferi) Species in the Central Region of South Korea

Parenting Experience of Mother of Teenage Girls with Conduct Disorder: A Parse's Method Study

Purpose: The aimof this study was to identify the parenting experience of mothers who have teenage girls with conduct disorders and to identify the meaning and structure of their experiences. Methods: This study was a qualitative research based on Parse`s researchmethod. Participants were 9mothers who had a daughter diagnosed with conduct disorder at a community hospital in the central region of South Korea. Results: The core concept on the parenting experiences of mothers of teenage girls with conduct disorder were survival against a violent environment, a sense of guilt related to the conduct disorder, confusion and frustration concerning mother`s role, and hope for the future. The experiences of thesemothers can be defined as the process of human becoming with powering and transforming while connecting-separating and enabling-limiting with valuing. Conclusion: This research is expected to contribute to understanding ofmothers` suffering and struggling and be useful in developing nursing care for clients with conduct disorder and their mothers.

Metagenomic assessment of the microbial diversity in ground pork products from markets in the North Central Region of South Korea

ABSTRACTThe purpose of this study was to characterize the microbial community in ground pork using molecular approaches. Forty six ground pork products were purchased from local stores in the north central area of South Korea. Aerobic plate counts varied 4.23 ± 5.14 × 105 CFU/g with the range between 5.00 × 103 and 1.85 × 106 CFU/g for ground pork samples. Four ground meat samples were further processed for metagenomic analysis. Pseudomonas species was the most relative abundant with a wide range occurring (1.72 to 77.7%) as part of the microbial genera in ground pork. Bacteria such as Carnobacterium, Yersinia, Photobacterium were also identified in ground pork. Despite the prominence of certain genera across all samples there was still extensive microbial diversity among ground pork products that originated from different slaughter houses and were processed in different markets. Such diversity indicates that designing interventions to extend shelf life may be hampered by the extensive variability in the microbial consortia associated with pork products. However, this diversity may be useful for developing microbial traceability signatures unique to a slaughter house or a particular market.

대학 영재원 영재선발시험의 단계별 연관성에 관한 연구 : 창의성의 일반 영역적 관점과 특수 영역적 관점에서

This study aims to analyze a selective examination for the gifted and talented from a domain-general and special standpoint. For this, we analyzed gifted and talented test results carried out by Gifted and Talented Education institute affiliated with the university of Education located in the central region of South Korea. This test consisted of three sections which are giftedness in the first round, academic aptitude in the second round and interview in the last round. I conducted the analysis of variance of the giftedness test result to the gifted and talented group in each subject from the domain-general point of view. As a result, the each group was not significant. This means that the gifted and talented in each subject has giftedness from the domain-general viewpoint. Secondly, I implemented the analysis of correlation among three test such as giftedness, academic aptitude and interview conducted during the selective process for the gifted and talented. The result was that they had a low or no correlations between them and were not significant. This demonstrated that each test checked a different area. That is, we came to realize that the first, second and third test evaluates a different area and in particular, with the result that the first and second test had a low or no correlations between both of them we realized that they evaluated a different area from a domain-special standpoint. The purpose of this study is meaningful to investigate in terms of how the selective test for the gifted and talented is conducted from a domain-general and special standpoint as a recent study viewpoint about the gifted and talented along with creativity. It is too limited to generalize this result because this test was sampled by one region but, this study indicates that we should take a domain-general and special standpoint into account when it comes to selection for the gifted and talented.

The Seroprevalence Rate, Vaccination Rate and Seroconversion Rate of Hepatitis A in Central Region of Korea

Acute hepatitis A (HAV) is markedly increasing recently on. Some patients with acute hepatitis A show severe clinical course. The seroprevalence rate of IgG anti-HAV has been changing with the regions and the times. Vaccination and seroconversion rate of HAV are not well known. In this study, we aimed to study the difference of seroprevalence rate of IgG anti-HAV according to various clinical factors and to know the vaccination rate and seroconversion rate below 10 years old in the central region of South Korea including Cheonan city.Seven hundred seventy two subjects were included in the study from January to September 2009. We analyzed seroprevalence rate of IgG anti-HAV according to sex, age, region, and other viral markers. We interviewed the history of vaccination(1st, 2nd) and analyzed seroconversion rate according to vaccination time below 10 years old.The total seroprevalence rate of IgG anti-HAV was 65.3%. The seroprevalence rate of IgG anti-HAV rate in 2nd, 3rd, and 4th decade was very low (1.9%, 18.8%, 44.8%). The vaccination rate of children was about 50%. The seroconversion rate after 1st, and 2nd vaccination were 85%, 96%.Catch-up vaccination for teenagers and young adults is needed. Immunizing children with HAV vaccine as a routine schedule should be considered.

Fault Plane Solutions for the Recent Earthquakes in the Central Region of South Korea

We analyzed fault plane solutions of the recent twenty-two earthquakes which occurred from 2004 to 2006 in the central part of the Korean Peninsula by using P- and S-wave polarities along with SH/P amplitude ratios. The fault plane solution shows that strike-slip fault is dominant here, especially for the events with local magnitude equal to or greater than 3.0. However, some events with local magnitude less than 3.0 show normal fault or strike-slip fault with normal components. In the case of strike-slip fault, its orientation is almost in the direction of NNE-SSW to NE-SW almost parallel to the general trend of faults, while the compressional axis of the stress field trends ENE to E-W. The result is almost consistent with the stress field in and around the Korean peninsula, as reported previously. We cannot give any appropriate explanations to the normal faulting events along the western offshore and inland areas whether it is related to the local stress changes or tectonically unidentified extensional structures. Thus, an extension of investigations is desirable to clarify the cause of such phenomena.

Preliminary GPS results and a possible neotectonic interpretation for South Korea

Crustal velocities within South Korea were estimated using GPS data and interpreted in terms of neotectonics. Twenty months of data for the seven GPS stations in South Korea were analyzed to estimate velocities relative to Taejon (DAEJ), a central region of South Korea. From the time series of horizontal position of each station, we estimated site velocities with an accuracy of 0.5 mm/year or better mostly. The relative velocities within the Korean peninsula are very small (∼1 mm/year), convertible to strain rates in the order of 0.01 ppm/yr. They indicate the Korean peninsula is likely to be tectonically more stationary than other countries in the East Asia, for example, Japan or Taiwan. The result of GPS analysis suggests a possibility that northwestward tectonic force due to the AM (Amurian plate)-PH (Philippine Sea plate) convergence affects the southeastern part of the Korean peninsula, of which the direction is curved due to internal faults in Korea, striking nearly perpendicular to the stress trend.