• Journal of Ecology and Environment
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• v.39 no.1
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• pp.61-70
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• 2016

Major objectives of the study were to analyze chemical and biological influences of the river ecosystem on the artificial weir construction at three regions of Sejong-Weir (S_j-W), Gongju-Weir (G_j-W), and Baekje-Weir (B_j-W) during 2008-2012. After the weir construction, the discharge volume increased up to 2.9 times, and biological oxygen demand (BOD) and electrical conductivity (EC) significantly decreased (p < 0.05). Also, the decrease of total phosphorus (TP) was also evident after the weir construction, but still hyper-eutrophic conditions, based on criteria by , were maintained. Multi-metric model of Index of Biological Integrity (IBI) showed that IBI values averaged 21.0 (range: 20-22; fair condition) in the B_wc, and 14.3 (range: 12-18; poor condition) in the A_wc. The model values of IBI in S_j-W and G_j-W were significantly decreased after the weir construction. The model of Self-Organizing Map (SOM) showed that two groups (cluster I and cluster II) of B_wc and A_wc were divided in the analysis based on the clustering map trained by the SOM. Principal Component Analysis (PCA) was similar to the results of the SOM analysis. Taken together, this research suggests that the weir construction on the river modified the discharge volume and the physical habitat structures along with distinct changes of some chemical water quality. These physical and chemical factors influenced the ecosystem health, measured as a model value of IBI.

• Korean Journal of Ecology and Environment
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• v.43 no.3
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• pp.428-436
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• 2010

This study was to evaluate water quality characteristics and ecological health using a mulimetric fish model in Taehwa-River watershed during May~September 2009. The ecological health assessments were based on the Index of Biological Integrity (IBI) using fish community and the multimetric model of Qualitative Habitat Evaluation Index (QHEI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. We also analyzed spatial patterns of chemical water quality over the period of 2000~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. Values of BOD and COD averaged $1.7\;mg\;L^{-1}$ (scope: $0.1{\sim}31.8\;mg\;L^{-1}$) and $3.6\;mg\;L^{-1}$ (scope: $0.4{\sim}33\;mg\;L^{-1}$), respectively during the study. Total nitrogen (TN) and total phosphorus (TP) averaged $2.8\;mg\;L^{-1}$ and $96.8\;{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypertrophic state. Also, TN and TP showed longitudinal increases toward the downriver reach. In the watershed, QHEI values varied from 67.5 (fair condition) to 164.5 (good condition) by the criteria of US EPA (1993). There was a abruptly decreasing tendency from T9 site in the QHEI values. According to 1st and 2nd surveys of Taewha River, multimetric model values of IBI was averaged 26.1 (n=14) with "good" condition (B) and the spatial variation was evident. Our results suggest that the mainstream sites was getting worse health condition along the river gradient due to inputs of the point and non-point sources from the urban (Ulsan city). Overall, dataset of IBI, QHEI, and water chemistry indicated that the ecological river health showed a downriver decline and the pattern was closely associated with habitat degradations and chemical pollutions as the waters pass through the urban region.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.15-24
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• 2015

The soil ecosystem is a complex system performing particularly complicated and varied functions, such as providing a habitat for organisms, acting as a medium for plant cultivation and growth, and functioning as a buffer against external materials in the environment. To assess whether these important functions of the soil ecosystem are executed appropriately, the concept of soil ecosystem health has been introduced, which is defined as the ability to perform the specific functions of the soil ecosystem. Understanding soil properties and soil indicators related to soil functions is essential to assess the soil health. In this study, systems, the indicators, and evaluation factors for assessing soil ecosystem health employed in a number of countries were investigated and discussed. In particular, it is necessary to introduce a technique for the evaluation of soil ecosystem health in Korea and to develop techniques and indicators appropriate to the soil ecosystem and status in Korea.

• Ecology and Resilient Infrastructure
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• v.8 no.2
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• pp.112-119
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• 2021

In 2012, the National Park Service conducted an ecological health assessment to efficiently preserve and manage the ecosystem. The need for improving pre-existing management indicators was recognized from the revised Natural Park Act because, while the indicators of the existing evaluation system focused on endangered species, ecosystem disturbance, diversity, water quality (BOD, DO), and habitat fragmentation, they did not reflect the lack of indicators for marine ecological assessment, policy changes, and the time demands. The evaluation results comprised a five-point grading system, which made the analysis of immediate changes, difficult. Therefore, the benthic pollution index (BPI) and habitat restoration indicators were added to improve the evaluation system. The National Park was assessed using 10 classifications, however, only four classifications were evaluated. The ratings were divided into five states, and ten classes were presented as pictograms. The assessment results showed a similar trend as the indicators were improved, increasing from level 3 to level 5. However, the results of the Wolaksan National Park after improvement in the indicators were lower than that before the improvement, whereas, for the Juwangsan National Park, it was higher. This study aims at contributing to the scientific and systematic management of the national park ecosystem by improving the ecological health assessment system.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.279-287
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• 2010

This study was to evaluate ecological conditions of Hyeongsan River watershed from April to September 2009. The ecological health assessments was based on Qualitative Habitat Evaluation Index (QHEI), water chemistry during 2000~2009, and the fish multi-metric model, Index of Biological Integrity (IBI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. Values of IBI averaged 25.4 (n=6), which is judged as a "fair" condition (C) after the criteria of Barbour et al. (1999). The distinct spatial variation was found in the IBI. Physical habitat health, based on the values of QHEI, varied from 76 in the downriver (H6) to 150.5 in the headwater (H1) and was evidently more disturbed in the downriver reach. Values of BOD and COD averaged 2.4 $mgL^{-1}$ (range: 0.3~13.8 $mgL^{-1}$) and 4.3 $mgL^{-1}$ (scope: 0.6~12.8 $mgL^{-1}$), respectively during the study period. Total nitrogen (TN) and total phosphorus (TP) averaged 3.0 $mgL^{-1}$ and 103.5 ${\mu}gL^{-1}$, respectively, indicating a severe eutrophication, and the nutrients increased more in the downriver than the headwater. Overall, physical, chemical and IBI parameters showed a typical downriver degradation along main axis of the river from the headwater-to-the downriver. This was mainly attributed to livestock waste and residential influences along with industrial discharge from the urban region.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.498-507
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• 2006

The main objective of present study was to evaluate how seasonal rainfall influenced natural habitat conditions of 10 metric habitat variables along with ionic conditions and suspended solids in the Woopo Wetland during August 2002-July 2003. Largest spatial variabilities in total suspended solids (TSS) occurred during the summer monsoon and the inorganic suspended solids (ISS), expressed as a inorganic proportion of total solids, showed linearly increasing trend from the upstream to downstream. This phenomenon was mainly attributed to counter flow of turbid water from the main Nakdong-River. During the flooding, ISS : TSS ratio showed large increases (92%) in the downstream than the upstream (43%). For this reason, transparency declined (mean=0.13 m, range=0.08-0.21 m) largely in the downstream reach and thus, chlorophyll-a concentration showed low values (range: $4.2-8.6\;{\mu}g\;L^{-1}$), indicating a direct influence on primary productivity or algal growth by inorganic turbidity. In the 2nd survey, ISS averaged 4.0 mg $L^{-1}$ (3.3-4.8 mg $L^{-1}$), thus the ISS decreased by 14 fold, compared to the ISS in the 1st survey during the flooding, while organic suspended solids (OSS) values were greater than those of ISS, indicating a dominance of organic solids. This condition was similar to solid contents in the 3rd survey, but showed a large difference compared to the 4th survey during the growing season. Habitat health assessments, based on 10 metric habitat variables, showed that QHEI values were greatest in the growing season (May) than any other seasons and largest spatial variations occurred in the 2nd survey. Overall, dataset suggest that seasonal episodic flooding during the monsoon may largely contribute nutrient cycling and sediment contents in the Woopo Wetland and Topyung Stream.

• Journal of the Korean housing association
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• v.20 no.5
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• pp.73-84
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• 2009

The purpose of this study was to provide basic information about the study of model development of sustainable housing area. This study identified the concept of sustainable development and the principles of the Habitat AgendaII. In the context, the 10 items of it were used to constitute the case study framework. This study found the planning characteristics through the case study of sustainable housing areas m Korea. The case for the study were 91 cases of Livable City Making of government and 43 cases of Urban Village Making of citizen group. And this study searched the missing point in the sustainable development concept of the practice cases. The research findings are as follows. First, the most practice cases had the aim of rehabilitation of the village functions. Second, in the cases of Livable City Making, residents practiced the rule as a participant for changing of their village. Third, in the cases of Urban Village Making, the scale were smaller than government's cases, but they tried the residents' health and welfare. Fourth, many cases applied the concept of sustainable development; environmental, social-cultural and economic sustainability, but some cases missed several principles of the Habitat Agenda.

• Animal cells and systems
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• v.16 no.1
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• pp.69-76
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• 2012

This study was conducted to examine how a low-head dam removal (partial removal) could affect benthic macroinvertebrate communities in a stream. Benthic macroinvertebrates and substrates were seasonally sampled before and after dam removal (March 2006-April 2007). Benthic macroinvertebrates and substrates were quantitatively sampled from immediately upstream (upper: pool) and downstream (lower: riffle) sites, the location of the dam itself (middle), and immediately above the impoundment (control: riffle). After the removal, species richness and density of benthic macroinvertebrates as well as the EPT group (Ephemeroptera, Plecoptera and Trichoptera) increased to higher levels than those before the removal, while functional feeding groups and habitat orientation groups changed more heterogeneously at the upper site. At the lower site, species richness and density decreased somewhat immediately after dam removal, which was associated with an increase of silt and sand, but recovered after monsoon floods which helped to enhance substrate diversity at the upper site. Decreased dominance index and increased diversity index in both the upper and lower sites are evidence of positive effects from the dam removal. In conclusion, we suggest that even a partial removal of a dam, resulting in increased substrate diversity in the upper site, could sufficiently help rehabilitate lost ecological integrity of streams without major habitat changes.

• International Journal of High-Rise Buildings
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• v.4 no.1
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• pp.39-44
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• 2015

This paper presents the structural health monitoring (SHM) of Shanghai Tower. In order to provide useful information for safety evaluation and regular maintenance under construction and in-service condition, a comprehensive structural health monitoring (SHM) system is installed in Shanghai Tower, which is composed of a main monitoring station and eleven substations. Structural responses at different construction stages are measured using this SHM system and presented in this study. Meanwhile, a detailed finite element model (FEM) is created and comparison of results between SHM and FEM is carried out. Results indicate that the time-dependent property of concrete creep is of great importance to structural response and the measured data can be used in FEM updating to obtain more accurate FEM models at different construction stages. Therefore, installation of structural health monitoring system in super-tall buildings could be considered as an effective way to assure structural safety during the construction process.

• Journal of Species Research
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• v.9 no.4
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• pp.492-531
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• 2020

This study is based on crane fly specimens collected from 1936-2019 and are in collections maintained at the United States National Museum, Smithsonian Institution, Washington DC, USA; the Snow Entomological Museum, University of Kansas, Lawrence, KS, USA; the Hungarian Natural History Museum in Budapest, Hungary, and the National Institute of Biological Resources, Incheon, South Korea. The genus Dicranophragma Osten Sacken, 1860 with two species D. (Brachylimnophila) transitorium (Alexander, 1941) and D. (Dicranophragma) melaleucum melaleucum (Alexander, 1933), is a new record for the Korean Peninsula. New findings of Dicranomyia (Erostrata) submelas Kato et al., 2018, Dicranoptycha venosa Alexander, 1924a, Austrolimnophila (Archilimnophila) subunicoides(Alexander, 1950b), A. (A.) unica (Osten Sacken, 1869), A. (Austrolimnophila) asiatica (Alexander, 1925), Conosia irrorata (Wiedemann, 1828), Eloeophila persalsa (Alexander, 1940), E. serenensis (Alexander, 1940), E. subaprilina (Alexander, 1919), E. ussuriana ussuriana (Alexander, 1933), E. yezoensis (Alexander, 1924b), Paradelphomyia chosenica Alexander, 1950b, and P. macracantha Alexander, 1957 are discussed. General information on genera and subgenera morphological characters, redescriptions of species based on Korean specimens, illustrations of both sexes, elevation range, period of activity, habitat information, general distribution, and a distribution map for the Korean Peninsula (including North Korea) are presented for each species.