• Journal of Korean Society of Forest Science
• /
• v.102 no.2
• /
• pp.239-246
• /
• 2013

This study observed changes of understory vegetation to evaluate the role of forest aggregate after 15% aggregated retention harvest in mature oak forest (> 100 years) in Gyungsangbukdo Bonghwagun in 2010 and 2011. Spontaneous responses of understory vegetation cover (%), species richness, abundance of plant growth forms (herbaceous and woody plants), and overall attributes (by Ordination analysis) were estimated in aggregate area (0.15 and n=36) and clear cut area (0.85 and n=192) in experimental site and control site (1 and n=300). Based on ordination analysis, overall change of species composition in aggregated sites were relatively lower than in harvest area. Right after treatment, total cover of cutted area slightly decreased from 15.6% to 14.7%, and species richness increased from 14 species to 22 species. Cover and richness in the both of aggregate and control sites increased. In plant growth forms, 15% aggregate harvest revealed positive effects on the abundance (cover and richness) of herbaceous plants than woody group. After retention treatment, overall, edge effect likely played major component of vegetation changes in aggregate forest and in harvested area, mechanical damage from harvest operation and change of forest structure by clear cutting were critical. As pre-treatment data, which are rare in ecological studies in Korea, were critical for interpretation between patterns that may have arisen from spatial distributions in the original forest, our experimental design have higher opportunity for long term monitoring on the effect of forest aggregate and vegetation regeneration in clear cutted area.

• Ecology and Resilient Infrastructure
• /
• v.2 no.3
• /
• pp.224-236
• /
• 2015

We conducted the algicidal activity screening tests using 10 L microcosm to investigate the possibility of the field application of naphthoquinone derivative Nq 4-6 compound as an algicide. We determined its application range to assess its algicidal effects on the phytoplankton and to evaluate the response of the planktonic community and the water environment to this chemical. From results of the microcosm experiments, Nq 4-6 compound showed high algicidal activity on the centric diatoms such as Stephanodiscus hantzschii and Cyclotella meneghiniana, but it had no effect on other phytoplankton. The abundance of S. hantzschii continuously increased in the control, but its cell density decreased 1 day after the Nq 4-6 treatment. In particular, Nq 4-6 showed algicidal activity of 94.4% against S. hantzschii 7 days after the treatment. The dominance index of phytoplankton community was lower in the treatment than in the control. The diversity index, richness index and evenness index of phytoplankton community was higher in the treatment. Environmental factors and biological factors did not show specific changes after the Nq 4-6 compound treatment. Therefore, the results of this study demonstrates that Nq 4-6 is an effective agent for the control of S. hantzschii blooms, and that the microcosm tests play a crucial role when assessing field application.

• Journal of Yeungnam Medical Science
• /
• v.12 no.2
• /
• pp.306-318
• /
• 1995

To evaluate the intractability of partial epileptic patients by variables, the author studied 113 patients (uncontrolled: 45, controlled: 68) who were admitted to the Department of Neurology, College of Medicine, Yeungnam University from January, 1991 to August, 1993. The results were as follows. The items related to complex partial seizures, multiple seizure types and a histories of status epilepticus or clusters of seizures were significantly associated with drug-refractoriness (p<0.01). A high frequency of seizures before evaluation was associated with a poor outcome(p<0.01). The presences of known etiology of seizures, neurologic abnormalities and psychiatric disturbance were associated with limited treatment responses(p<0.01, p<0.05, p<0.01). An abnormal EEG findings such as background slowing, focal slowing, epileptiform discharges or secondarily bilateral synchrony were statistically significant (p<0.01). Age at onset, sex, distribution of epileptic foci, duration of seizure before evaluation, family history and abnormal neuroradiologic findings were not statistically significant. By these results, it was suggested that having at least four factors of the above variables were associated with limited treatment response.

• Journal of the Korea Convergence Society
• /
• v.12 no.3
• /
• pp.297-304
• /
• 2021

This study aims not only to access the visual thought-oriented approach that has been implemented in established art therapy and education but also to integrate language education and therapeutic approach to support the development of school-age children. Thus, text mining technique was applied to search for areas where different areas of language and art can be integrated. This research was conducted in accordance with the procedure of basic research, preliminary DB construction, text screening, DB pre-processing and confirmation, stop-words removing, text mining analysis and the deduction about the convergent areas. These results demonstrated that this study draws convergence areas related to regional, communication, and learning functions, areas related to problem solving and sensory organs, areas related to art and intelligence, areas related to information and communication, areas related to home and disability, topics, conceptualization, peer-related areas, integration, reorganization, attitudes. In conclusion, this study is meaningful in that it established a framework for designing an activity-centered convergence program of art and language in the future and attempted a holistic approach to support child development.

• Journal of Digital Convergence
• /
• v.20 no.4
• /
• pp.193-202
• /
• 2022

The purpose of this study is to propose an effective informatization policy by categorizing consumer groups according to the level of digital divide and identifying the characteristics of each type. For this end, a total of 402 data were collected through an online and on-site surveys targeting consumers with internet experience, and the data were analyzed using the SPSS 26.0 program. As a result of conducting a K-means cluster analysis based on access to, capability, and utilization of digital devices, four consumer groups were categorized: 'device lover', 'proficient user', 'general user', and 'digital alienated'. By consumer type, significant differences were found in demographic characteristics, social capital, perception of the future information society, attitude toward technology as innovativeness, discomfort and familiarity, which are the antecedent variables of the digital divide. Significant differences in digital device satisfaction and intention to use, which are outcome variables of the digital divide, were also confirmed by consumer type. This study is academically and practically valuable in that it proposes customized informatization policies for each consumer group according to the level of digitization.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.3
• /
• pp.18-29
• /
• 2022

Recently, cooperative intelligent transport systems (C-ITS) testbeds have been deployed in great numbers, and advanced autonomous driving research using V2X communication technology has been conducted actively worldwide. In particular, the broadcasting services in their beginning days, giving warning messages, basic safety messages, traffic information, etc., gradually developed into advanced network services, such as platooning, remote driving, and sensor sharing, that need to perform real-time. In addition, technologies improving these advanced network services' throughput and latency are being developed on many fronts to support these services. Notably, this research analyzed the network latency requirements of the advanced network services to develop a remote driving service for the droid type low-speed robot based on the 3GPP C-V2X communication technology. Subsequently, this remote driving service's performance was evaluated using system modeling (that included the operator behavior) and simulation. This evaluation showed that a respective core and access network latency of less than 30 ms was required to meet more than 90 % of the remote driving service's performance requirements under the given test conditions.

• Korean Journal of Environment and Ecology
• /
• v.37 no.1
• /
• pp.59-69
• /
• 2023

This study was carried for the purpose of using basic data for vegetation management plans by analyzing the current status of herbaceous community and Salix spp. community at Janghang Wetland in Han-river estuary. In order to investigate the vegetation status, the 50 plots were investigated and analyzed using the quadrat and Braun-Branquet method. In the herbaceous community, were found a total of 31 taxa of 11 families, 24 genera, 28 species, and 3 variants. A total of 42 taxa of 16 families, 33 genera, 39 species and 3 variants were appeared in the Salix subfragilis community, and a total of 46 taxa with classification of 19 families, 37 genera, 43 species, and 3 varieties were founded in the Salix koreensis community. As for the analysis of life-form and dominance, the hydatophytes was relatively high in the Salix subfragilis community, the hemicryptothytes was high in herbaceous community and therophytes was high in Salix koreensis community. As a result of correlation analysis of electrical conductivity(EC) and exchangeable sodium(Na+) in the soil, hydatophytes and hemicryptothytes showed a negative correlation, and therophytes showed a positive correlation. Therefore, it was analyzed that Salix koreensis and therophytes have a high rate of appearance in relatively dry and salty soil. Salix subfragilis, hydatophytes, and hemicryptothytes have a high rate of appearance in low salt concentrations and wet areas.

• Korean Journal of Clinical Laboratory Science
• /
• v.54 no.1
• /
• pp.68-72
• /
• 2022

Angioimmunoblastic T-cell lymphoma (AITL) is a lymphoproliferative disorder of mature T follicular helper cells. Atypical lymphoid cells were observed in the bone marrow of an 80-year-old woman, and the flow cytometric determined immunophenotypes of B-cells were unusual, that is, CD19+, CD20-, and CD22- with lambda light chain restriction. Initially, we suspected BM involvement of B-cell lymphoma based on the presence of abnormal B-cells. However, the patient was diagnosed with AITL involving BM. A re-analysis of flow cytometric immunophenotyping revealed a minor, aberrant T-cell population, and the lambda light chain restriction observed by surface staining was considered non-specific binding. This case demonstrates B-cells in patients with EBV-positive T-cell lymphoma may exhibit immunophenotypes resembling those of plasma cells, and that proliferation of abnormal B-cells or plasma cells could also potentially mask underlying T-cell lymphoma. A more integrated approach is required for accurate diagnosis.

• Journal of Wetlands Research
• /
• v.18 no.1
• /
• pp.32-38
• /
• 2016

The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.7
• /
• pp.924-942
• /
• 2021

The expansion of the Changjiang Diluted Water (CDW) plume during summer is known to be a major factor influencing phytoplankton diversity, community structure, and the regional marine environment of the northern East China Sea (ECS). The discharge of the CDW plume was very high in the summer of 2020, and cruise surveys and stationary monitoring were conducted to understand the dynamics of changes in environmental characteristics and the impact on phytoplankton diversity and community structure. A cruise survey was conducted from August 16 to 17, 2020, using R/V Eardo, and a stay survey at the Ieodo Ocean Research Station (IORS) from August 15 to 21, 2020, to analyze phytoplankton diversity and community structure. The southwestern part of the survey area exhibited low salinity and high chlorophyll a fluorescence under the influence of the CDW plume, whereas the southeastern part of the survey area presented high salinity and low chlorophyll a fluorescence under the influence of the Tsushima Warm Current (TWC). The total chlorophyll a concentrations of surface water samples from 12 sampling stations indicated that nano-phytoplankton (20-3 ㎛) and micro-phytoplankton (> 20 ㎛) were the dominant groups during the survey period. Only stations strongly influenced by the TWC presented approximately 50% of the biomass contributed by pico-phytoplankton (< 3 ㎛). The size distribution of phytoplankton in the surface water samples is related to nutrient supplies, and areas where high nutrient (nitrate) supplies were provided by the CDW plume displayed higher biomass contribution by micro-phytoplankton groups. A total of 45 genera of nano- and micro-phytoplankton groups were classified using morphological analysis. Among them, the dominant taxa were the diatoms Guinardia flaccida and Nitzschia spp. and the dinoflagellates Gonyaulax monacantha, Noctiluca scintillans, Gymnodinium spirale, Heterocapsa spp., Prorocentrum micans, and Tripos furca. The sampling stations affected by the TWC and low in nitrate concentrations presented high concentrations of photosynthetic pico-eukaryotes (PPE) and photosynthetic pico-prokaryotes (PPP). Most sampling stations had phosphate-limited conditions. Higher Synechococcus concentrations were enumerated for the sampling stations influenced by low-nutrient water of the TWC using flow cytometry. The NGS analysis revealed 29 clades of Synechococcus among PPP, and 11 clades displayed a dominance rate of 1% or more at least once in one sample. Clade II was the dominant group in the surface water, whereas various clades (Clades I, IV, etc.) were found to be the next dominant groups in the SCM layers. The Prochlorococcus group, belonging to the PPP, observed in the warm water region, presented a high-light-adapted ecotype and did not appear in the northern part of the survey region. PPE analysis resulted in 163 operational taxonomic units (OTUs), indicating very high diversity. Among them, 11 major taxa showed dominant OTUs with more than 5% in at least one sample, while Amphidinium testudo was the dominant taxon in the surface water in the low-salinity region affected by the CDW plume, and the chlorophyta was dominant in the SCM layer. In the warm water region affected by the TWC, various groups of haptophytes were dominant. Observations from the IORS also presented similar results to the cruise survey results for biomass, size distribution, and diversity of phytoplankton. The results revealed the various dynamic responses of phytoplankton influenced by the CDW plume. By comparing the results from the IORS and research cruise studies, the study confirmed that the IORS is an important observational station to monitor the dynamic impact of the CDW plume. In future research, it is necessary to establish an effective use of IORS in preparation for changes in the ECS summer environment and ecosystem due to climate change.