• Korean Journal of Environment and Ecology
• /
• v.35 no.3
• /
• pp.265-276
• /
• 2021

This study investigated the characteristics of fish communities and river health in the Sincheon stream of Imgin River between April and October 2019. The survey collected 3,677 objects in 30 species belonging to 12 families from 23 survey stations. The dominant and subdominant species were Zacco platypus (28.4%) and Oryzias sinensis (13.6%), respectively, followed by Z. koreanus (11.8%), Rhynchocypris oxycephalus (11.7%), Carassius auratus (9.6%), and Pseudorasbora parva (7.9%) in that order. Among the fish species collected, 10 (33.3%) were endemic species in Korea. The exotic species were 5 (16.7%), including Micropterus salmoides, Lepomis macrochirus, Cyprinus carpio (Israeli type), Poecilia reticulata, and Xiphophorus maculatus. The land-locked species included Cottus koreanus and Rhinogobius brunneus, while C. koreanus was a climate change-sensitive species. The dominance of the fish community was low, and the diversity was high in the Sincheon mainstream, Sudongcheon and Cheongdamcheon, whereas Dongducheon and Sangpaecheon showed higher dominance and low diversity. The river health was very good and good in the uppermost and Sudongcheon areas, whereas the upper stream was normal, and the middle and lower streams were poor and very poor, respectively. The water quality was also mostly poor or very poor from the midstream to the downstream, and only Sudongcheon was very good. Therefore, the water quality had a great impact on fish habitat and eventually affected river health significantly. Although the water quality of Shincheon has improved each year, the introduction of several foreign species had a very negative effect. Improvement of river health in Shincheon requires water quality improvement and management of exotic fish species.

• Journal of the Korea Society for Simulation
• /
• v.31 no.3
• /
• pp.1-10
• /
• 2022

Defense fields widely operate unmanned systems to lower vulnerability and enhance combat effectiveness. In the navy, swarm unmanned surface vehicles(USVs) form a cluster within communication range, share situational awareness information among the USVs, and cooperate with them to conduct military missions. This paper proposes an interface system, i.e., Interface Adapter System(IAS), to achieve inter-USV and intra-USV interoperability. We focus on the mission planning subsystem(MPS) for interoperability, which is the core subsystem of the USV to decide courses of action such as automatic path generation and weapon assignments. The central role of the proposed system is to exchange interface data between MPSs and other subsystems in real-time. To this end, we analyzed the operational requirements of the MPS and identified interface messages. Then we developed the IAS using the distributed real-time middleware. As experiments, we conducted several integration tests at swarm USVs simulation environment and measured delay time and loss ratio of interface messages. We expect that the proposed IAS successfully provides bridge roles between the mission planning system and other subsystems.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2B
• /
• pp.225-236
• /
• 2008

The techniques to calculate the probability precipitation for the design of hydrological projects can be determined by the point frequency analysis and the regional frequency analysis. Probability precipitation usually calculated by point frequency analysis using rainfall data that is observed in rainfall observatory which is situated in the basin. Therefore, Probability precipitation through point frequency analysis need observed rainfall data for enough periods. But, lacking precipitation data can be calculated to wrong parameters. Consequently, the regional frequency analysis can supplement the lacking precipitation data. Therefore, the regional frequency analysis has weaknesses compared to point frequency analysis because of suppositions about probability distributions. In this paper, rainfall observatory in Korea did grouping by cluster analysis using position of timely precipitation observatory and characteristic time rainfall. Discordancy and heterogeneity measures verified the grouping precipitation observatory by the cluster analysis. So, there divided rainfall observatory in Korea to 6 areas, and the regional frequency analysis applies index-flood techniques and L-moment techniques. Also, the probability precipitation was calculated by the regional frequency analysis using variable kernel density function. At the results, the regional frequency analysis of the variable kernel function can utilize for decision difficulty of suitable probability distribution in other methods.

• Journal of Animal Science and Technology
• /
• v.55 no.5
• /
• pp.381-388
• /
• 2013

This study examined the effects of sex in different group sizes of Hanwoo calves. The growth performance including the mean daily gain, feed conversion rate, behavioral characteristics, and blood parameters in Hanwoo calves were investigated. A total of 54 heads of Hanwoo calves were housed separately at 4 heads per group, 3 heads per group, and 2 heads per group per pen. In the heifer calves, except for those 10 months of age, the growth performance was improved by increasing the group size, which was similar to steer calves (p<0.05). The heifer calves housed in 3 heads group spent more time lying down (p<0.05). The steer calves spent more time standing in the 3 heads group, lying down (2 heads group), and walking (4 heads group). The heifer calves housed in 2 heads group had a lower frequency of drinking, self-grooming, pairwise grooming, and fighting (p<0.05). On the other hand, the steer calves in the 4 heads group had a higher frequency of drinking, rubbing, and fighting (p<0.05). The white blood cell and cortisol were highest in the heifer calves in the 2 heads group (p<0.05).

• Korean Journal of Ecology and Environment
• /
• v.45 no.1
• /
• pp.72-81
• /
• 2012

We investigated the effects of acid mine drainage (AMD) from abandoned coal mines on benthic macroinvertebrate communities in the upper reaches of the Nakdong River from May to October in 2009. Qualitative and quantitative sampling (Surber sampler: $50{\times}50$ cm; mesh size, 0.2 mm) was conducted at 7 study sites and 3 control sites in the study area. We thus sampled 117 species belonging to 53 families, 15 orders, 6 classes, and 5 phyla; the Ephemeroptera, Plecoptera, and Trichoptera group (EPT-group) represented the majority of the benthic macroinvertebrate community (71 species; 64.5%). In the quantitative sampling, a total of 11,575 individuals belonging to 58 species of benthic maroinvertebrates were sampled from the study sites (Sites 1-7), whereas 2,844 individuals belonging to 79 species were sampled from the control sites (Sites A-C). Tolerant species such as oligochaetes, $Epeorus$ $pellucidus$, $Baetis$ $fuscatus$, Hydropsychidae species, and Chironomidae species were predominant in the study sites. The community indices for the study sites, such as MacNaughton's dominance index (DI) (mean${\pm}$SD, $0.52{\pm}0.21$; range, 0.33-0.85) and the Shannon diversity index ($H^{\prime}$) ($2.06{\pm}0.60$; 1.06-2.57), were different from those for the control sites (DI: $0.29{\pm}0.07$, 0.22-0.35; $H^{\prime}$: $3.13{\pm}0.14$; 3.03-3.30). In the study sites, shredders and scrapers were scarce, whereas gathering-collectors (mainly Chironomidae species) were relatively abundant, as were clingers and burrowers. The detrended correspondence analysis (DCA) and similarity analyses showed that benthic macroinvertebrate communities in the study sites were clearly separated from those of the control sites, with the greatest dissimilarity being noted at the uppermost study site (Site 1), which is located close to an abandoned coal mine. The Korean saprobic index (KSI) and the ecological score using benthic macroinvertebrates (ESB) showed that the uppermost study site (Site 1) was ${\alpha}$-mesosaprobic or heavily polluted, whereas other study sites were in a fair or relatively good condition.

• Korean Journal of Ichthyology
• /
• v.33 no.2
• /
• pp.126-141
• /
• 2021

Fauna of freshwater fish and community structure were investigated at 13 sites in the Deogyusan National Park, Korea from 2014 to 2018. During the period, a total of 8 families, 21 species, and 8,716 individuals of fishes were collected. The number of fish collected over the past five years from 2014 to 2018, were 17 species and 2,280 individuals, 17 species and 1,579 individuals, 17 species 1,905 individuals, 17 species and 1,384 individuals, and 15 species and 1,568 individuals, respectively. There were 13 Korean endemic species including Iksookimia koreensis and Coreoleuciscus splendidus, etc. Only in Wondangcheon Stream, two endangered species were identified, and Hemibarbus mylodon was collected continuously except in 2015, and Pseudopungtungia nigra was observed every year. And two exotic species such as Oncorhynchus masou masou and Oncorhynchus mykiss occurred in Gucheongdongcheon Stream sites. The dominant species was Rhynchocypris oxycephalus and the sub-dominant species was Zacco koreanus and there was no difference by year. The fish community structure of Deogyusan National Park was varied depending on the sites and the year. Most of the survey sites located upper stream where the river structure is Aa river type showed poor community analysis results. On the other hand, the upper-mid stream sites including the Bb type showed better results. As a result, the Wondangcheon Stream sites had the most diverse and stable community structure. Similarity dendrogram was divided into 4 groups, mainly reflecting the characteristics of the habitat. The flagship species of the Deogyusan National Park, Rhynchocypris kumgangensis, was constantly observed during the investigation period. Compared to the previous survey, the number of species increased from 2004 (12 species) and decreased from 2009 (22 species).

• Clinical and Experimental Reproductive Medicine
• /
• v.37 no.2
• /
• pp.99-113
• /
• 2010

Objective: It has been recently reported that very small stem cells with pluripotency are detected in murine and human. The purposes of this study are to confirm whether very small putative stem cells (VSPSCs), which have the proper characteristics of stem cells as well as the expression of stem cell markers, are detected in human endometrium. Methods: The endometrial cells of 5 women, which were obtained by endometrial biopsy, were cultured for 2 weeks and were confirmed for the expressions of alkaline phosphatase, OCT-4 and CXCR4 by immunochemistry. Subsequently VSPSCs were separated by percoll density gradient method and were cultured. Also VSPSCs and their derived cells were confirmed for the expressions of OCT-4 and CXCR4. Results: The colonies, which is composed with VSPSCs less than 3 ${\mu}m$ and the 5~15 ${\mu}m$ sized hyperchromatic round cells, were detected in the endometrium of all of women and showed the strong expressions of alkaline phosphatase, OCT-4 and CXCR4. In culture after the separation of VSPSCs by percoll, these cells showed the morphological and functional characteristics of stem cells; self-renewal, colony formation, embryoid body-like formation and differential plasticity. VSPSCs formed gradually the 5~15 ${\mu}m$ sized hyperchromatic round cells and the 10~20 ${\mu}m$ sized sphere-shaped cells by cell-to-cell aggregation or cell fusion. Then these cells differentiated the various cells including fibroblast-like cells, nerve-like cells and endothelium-like cells. VSPSCs and their derived cells often showed the strong expressions of OCT-4 and CXCR4. Conclusion: VSPSCs less than 3 ${\mu}m$ and their derived cells are detected in human endometrium and these cells have the proper characteristics of stem cells and the expressions of stem cell markers as alkaline phosphatase, OCT-4 and CXCR4.

• Journal of the Korean Society for information Management
• /
• v.35 no.1
• /
• pp.13-32
• /
• 2018

The purpose of this study is to analyze the association among the subject areas of big data research papers. The subject group of the units of analysis was extracted by applying co-citation networks, and the rules of association were analyzed using Apriori algorithm of R program, and visualized using the arulesViz package of R program. As a result of the study, 22 subject areas were extracted and these subjects were divided into three clusters. As a result of analyzing the association type of the subject, it was classified into 'professional type', 'general type', 'expanded type' depending on the complexity of association. The professional type included library and information science and journalism. The general type included politics & diplomacy, trade, and tourism. The expanded types included other humanities, general social sciences, and general tourism. This association networks show a tendency to cite other subject areas that are relevant when citing a subject field, and the library should consider services that use the association for academic information services.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.3 no.2
• /
• pp.37-47
• /
• 2000

Since 1995, agropolitan cities have been created, in order to pursue the balanced development between urban cities and its surrounding rural counties. However, the inequality of regional level that was caused by indiscreet development has become the ever-serious problems recently. Therefore, this study aims to analyze regional characteristics and patterns for setting up the sustainable spatial planning. Firstly, the regional characteristics were summarized by five factors; development-oriented factor, agricultural factor, living environmental factor, rice growing, fruit gardening factor. The regional patterns were classified with five patterns using cluster analysis; orchard farming, farming of medium and small size, small stagnation, under urbanization, mixed urban-rural properties, and industry of southeastern seashore. Accuracy of the results by discrimination analysis showed that pattern II, V, and VI were confidence level of 100%, but the others had nearly 90% confidence level.

• The Journal of the Korea Contents Association
• /
• v.9 no.2
• /
• pp.51-59
• /
• 2009

Interactive multimedia broadcasting can serve various additional information of object in multimedia because of the commercialized data broadcasting by communication and broadcasting convergence. One of the most important factors in interactive multimedia broadcasting is User-Centric Interoperability. The higher User-Centric Interoperability, the more information of user-interest objects are served quickly by user request. This proposed method finds own area of the object in mask video and divides the area into equal parts. And then it store as a form of bitsum after clustering the area. As a result of experiment, We confirm the method is efficient to use space for storing position information of the object.