• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.387-394
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• 2000

Water pollution characteristics were investigated in the Kyongan stream and major inlet parts of Paltang Reservoir from April to July, 2000. Water quality in the Kyongan stream was extremly deteriorated by treated wastewater discharge at near sewage wastewater treatment plant (SWTP) located in the upstream, and it is likely to influence eutrophication of the lower part of the stream. Water quality of the Kyongan stream showed a typical hypertrophic condition. Influxed concentrations with $NH_4$ and SRP into the main stream from SWTP were declined precipitously as water flowed toward the lower part of the stream, and chlorophyll- a explosively increased in the midstream. Average concentrations of $NH_4$, SRP and chlorophyll-a in the main stream were $1,343\;{\mu}g\;N/l$, $1,779\;{\mu}g\;P/l$ and $188\;{\mu}g\;l$, respectively. Particularly, phosphorus load was very high, and its influence on the algal growth stimulation was remarkable. In comparison with the water quality inflowing into Paltang Resevoir, pollution status of the Kyongan stream was more worse than that in the Pukhan River and the Namhan River. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate eutrophication of Paltang Reservoir, and requires further necessary controls of inorganic phosphorus loading.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.55-59
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• 2006

The objectives of this study, an analysis of the morphological characteristics among six provenances of a rare Rhododendron micranthum could be used for the conservation of gene resources and could provide information on superior trees selection. The following results were obtained. Approximately Mt.worak region showed larger values at petal character. On the other hand, Bonghwa region showed smaller values at petal character. Yeonha-ri region showed larger values at leaf character. On the other hand, Bonghwa region showed smaller values at leaf character. The results of principal component analysis (PCA) for morphological characteristics showed that the first for principal components(PC's) explained 41.6% of the total variation. From th third PC explained 81.5% of the total variation. The first PC was correlated with those characteristics that were mainly related to the Petal length (PL), Leaf length (LL) width (LW), Stigma length (SL). The second PC was correlated with the Petiole length (PTW), Anther length (AL). The third PC was correlated with the Flower pedicel length (FPL), Filament length (FL). Therefore, these characteristics was important to analysis of the variation for morphological characteristics among provenances of Rhododendron micranthum. Cluster analysis using single linkage method based on morphological characteristics showed that six provenances of Rhododendron micranthum could be clustered into three groups. Group I is Jicdong-ri, Group II is Mt.worak and Yeonha-ri, and Group III is Taeback, Bonghwa, and Samcheok. These results corresponded well with that of principal component analysis.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.302-306
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• 2016

There are various methods to evaluate tree vigor. Cambial electrical resistance represents tree vigor using the method of electrophysiological diagnosis. This study investigated the vigor of several tree species using Shigometer, and compared the differences among the species. The factors, such as foliation, trunk orientation and bark temperature, which affect electrical resistance were also investigated. The needle penetration into cambium was controlled to keep the depth consistent in order to minimize measurement error. Each of three trees were selected from Zelkova serrata, Ginkgo biloba, Metasequoia glyptostroboides, Pinus koraiensis, and Liriodendron tulipifera. The electrical resistances were measured at 60 and 120 cm height of the stem in 4 directions from March until May 2011. The soil conditions in surrounding areas and tree stress responses were also measured. The results were analyzed for the relationship between electrical resistance and the affecting factors. The electrical resistance showed a relatively higher level before foliation until mid-March. The values started to decline from April and recorded a minimal level on May 11. The changes of soil moisture, soil electric conductivity, and tree stress responses during the measurement period showed a similar trend to that of electrical resistance. The Pinus koraiensis, an evergreen conifer, showed few changes on the electrical resistance values during the measurement period. Zelkova serrata, Ginkgo biloba, and Metasequoia glyptostroboides showed the highest bark temperatures and lowest electrical resistances at their south-facing stem. Shigometer can provide measures simple to assess tree vigor in the fields, and to the management of trees.

• Journal of muscle and joint health
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• v.13 no.2
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• pp.83-93
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• 2006

Purpose: The purpose of the study was to compare the effects of Tai Chi self-help program and Tai Chi exercise in patients with osteoarthritis. Methods: quasi experimental design was utilized for the study to compare the effects after implementing tai chi self-help program and Tai Chi exercise for 6 weeks. The subjects of the study was osteoarthritis patients who visited to two Public Health Centers in Gyunggi-do from August to December, 2005. Total of 25 OA patients agreed to participate in the study, and 10 tai chi self-help program group and 9 Tai Chi exercise group were included for the final analysis after 6 weeks. Tai Chi self-help program was provided twice a week, 2 hours per session (one hour for tai chi exercise, one hour for self help program) for 6 weeks, and Tai Chi exercise group was provided once a week, 2 hours per session for 6 weeks. Outcome measures include flexibility, 6 m walking, and balance. Mann-Whitney U test of SPSS WIN 11.0 was utilized to compare the group differences. Results: The subjects of both program participants were not improved in their arm flexibility, and the difference was not significant. Tai chi self-help group improved more in their 6 m walking ability than Tai Chi exercise group, but the difference was not significant (F=.000, p>.05). Tai chi self-help group improved more in their balance than Tai Chi exercise group, but the difference was not significant (Rt: U=.24, p>.05; Lt: F=2.60, p>.05). Conclusion: The provision of both Tai Chi self-help program and Tai Chi exercise can lead improvement of 6 m walking, and balance, but the group difference was not significant. A rigorous research design should be further utilized to identify the potential benefits for this population.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.119-125
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• 2001

Total bacterial density was investigated in the main stream and tributaries of the Kyongan Stream and inlet parts of Paltang Reservoir from September 2000 to February 2001 by acridine orange direct count (AODC) method. Total bacterial number in the Kyongan Stream was mainly under influence of the effluent discharge of sewage wastewater treatment plant (SWTP) located in the upstream or downstream. Decreasing rate with water flowing distance (km) in the main stream is $0.13\;{\time}\;10^6$ cells/ml, and it was estimated to much accumulating quantity on the stream bed during transport to downstream. Average values of total bacterial number in September${\sim}$October, November and December${\sim}$February were range $1.74{\sim}3.10{\time}10^6$, $1.86{\sim}7.30{\time}10^6$ and $4.56{\sim}8.75{\time}10^6$cells/ml, respectively, and were high at low temperature than that of high temperature period. Total bacterial number was more abundant at below $10^{\circ}C$ with $2.1{\sim}3.0$ folds than at above $10^{\circ}C$. Water quality by total bacterial number was classify to eutrophic and the potential of wastewater treated effluent for the microbial contamination assessed to very high. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate bacterial impact of Paltang Reservoir as well as the Kyongan Stream.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.251-259
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• 2000

Monthly variations of physico-chemical and biological parameter were determined in near the Kum River mouth at lower discharge period from January 1998 to September 1999. The characteristics of water quality was showed hypertrophic with average values of total nitrogen (TN), total phosphorus (TP), chlorophyll-a and transparency are 3.9 mg N/l, $160\;{\mu}g/l$, $73\;{\mu}g/l$ and 0.8 m, respectively. Among a nitrogen component, inorganic and organic nitrogen comprised 34% and 66% of TN, $NH_4$ and $NO_3$ comprised 30% and 70% of inorganic nitrogen respectively. SRP concentration comprised below 9% of TP. TN/TP and DIN/SRP ratio in winter were higher than in summer. SRSi fluctuation was very wide as ranged from 0 to 3.0 mg Si/l and the highest after flood event in summer. Long-term depleted pattern of Si was observed, that is considered to be important nutrient for algal growth. Chlorophyll-a concentration was very high as $113\;{\mu}g/l$, $162\;{\mu}g/l$ in winter and summer respectively, which persisent bloomed diatom Stephanodiscus and blue-green algae Microcystis. In consequence, water quality management of these periods are considered very important.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.244-250
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• 2000

Algal growth potential (AGP) bioassay were conducted to assess the water quality and fertility in the Kum River from March 1998 to June 1999. AGP values were always the highest at the conjuction site of the Kapchon, which is a tributary of the Kum River. Average value of AGP by Microcystis aeruginosa in the main river and tributary was 17.0 mg dw/l, 48.3 mg dw/l, respectively. AGP values decreased towards the lower part of the river and consisted in the water quality or nutrient analysisresults. Among the tributaries, AGP of the Kapchon, Mihochon and Soksongchon were relatively high, and the average value was 161.2, 50.3 and 125.6 mg dw/l, respectively. AGP value in the Yukuchon was lowest among the study stations with <2.7 mg dw/l. Water quality in the lower part of the Kum River deteriorated in drought season, and the AGP values of this season were higher than those in other seasons. Based on correlation analysis between AGP results and nutrients, limiting nutrient appeared to be P because SRP (r = 0.99) was higher than other nutrients, and N uptake in algal growth was preferred by $NH_4$ rather than $NO_3$. The variation of AGP was different according to localities and seasons, and it was related to nutrient fluctuation in the inlet tributary. Water quality status according to AGP was assessed to be eutrophic.

• Journal of Wetlands Research
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• v.13 no.2
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• pp.231-242
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• 2011

Recently, the green spaces in the urban areas were greatly reduced due to urbanization and industrialization. As urban structures such as roads and buildings are built, the amount of impervious area within a watershed increases. High impervious surfaces are the common causes of high runoff volumes as the soil infiltration capacity decreases and the volume and rate of runoff increase thereby decreasing the groundwater recharge. These effects are causing many environmental problems, such as floods and droughts, climate change, heat island phenomenon, drying streams, etc. Most cities attempted to reduce sewer overflows by separating combined sewers, expanding treatment capacity or storage within the sewer system, or by replacing broken or decaying pipes. However, these practices can be enormously expensive than combined sewer overflows. Therefore, in order to improve these practices, alternative methods should be undertaken. A new approach termed as "Low Impact Development (LID)" technology is currently applied in developed countries around the world. The purpose of this study was to effectively manage runoff by adopting the LID techniques. Small Constructed Wetland(Horizontal Subsurface Flow, HSSF) Pilot-scale reactors were made in which monitoring and experiments were performed to investigate the efficiency of the system in removing pollutants from runoff. Based on the results of the Pilot-plant experiments, TSS, $COD_{Cr}$, TN, TP, Total Pb removal efficiency were 95, 82, 35, 91 and 57%, respectively. Most of the pollutants were reduced after passing the settling tank and the vertical filter media. The results of this study can contribute to the conservation of aquatic ecosystems and restoration of natural water cycle in the urban areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1063-1069
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• 2007

우리나라의 하천환경은 1990년대 이전의 산업화와 인구증가를 수반한 고도성장기를 거치면서 이수성 및 치수성만을 강조하며 개수되고 관리되었다. 그 결과 하천은 획일적인 단면과 저수로 및 제방이 콘크리트화되면서 하천의 자정능력은 감소되었고, 하천을 중심으로 생활하는 동물들의 서식처 기능을 상실해 하천생태계가 위협받고 있다. 하천공사에 자연형 하천공법이 도입되기 시작하여 자연형 하천공사가 이루어지고 있지만 생태환경의 관점보다는 조경 및 경관적, 그리고 위락적인 관점에서 공원화에 주안점을 두고 있어 하천의 생태적 특성의 반영이 부족하다는 평가를 듣고 있는 실정이다. 따라서 본 연구에서는 향후의 하천공법이 자연적 기능들 중 생물서식처 기능을 보다 깊이 다루어야 한다는 필요성을 고려하여, 먹이사슬의 최상위에 있을 뿐만 아니라 하천환경의 건강도를 판단할 수 있는 수환경의 지표종이라 불리는 수달(Lutra lutra)을 대상으로 배설물에 의한 출현빈도와 하천환경 요인들에 대한 상관관계를 분석하여 수달 서식지 복원을 위한 하천정비의 기초자료를 제공하는 데 그 목적이 있다. 이를 위해 현재 수달이 서식하고 있는 섬진강 지류인 서시천을 연구 대상지점으로 하여 5개 구간을 선정하였으며, 각 구간에 대한 계절별 수달의 배설물 분포를 조사하여 출현빈도를 나타내었다. 또한 먹이, 지형, 식생, 기상인자를 포함한 하천환경 요인들에 대한 자료를 각 계절별로 구축하였으며, 이를 수달의 출현빈도와의 상관관계를 조사하는데 활용하였다. 본 연구의 결과는 환경 기술적으로는 멸종위기종의 복원, 사회경제적으로는 하천정비사업의 방향제시 등의 기대효과를 가져올 수 있으리라 생각되며 분석된 인자들은 수달 서식지를 위한 하천정비의 기초자료에 유용할 것으로 보인다.따른 유량측정망을 구축하는 것이다.의 의사결정 지원 도구가 될 것이다. 따라서, 본 연구에서는 도시유역의 물순환 해석을 위한 일련의 과정, 즉 자료의 조사 및 취득에서부터 물순환 해석 모형을 이용한 정량적 현황파악, 물순환 개선 기법 및 평가를 수행함에 있어 주요 착안점 및 실무에서의 기술적 가이드를 제공하고자 하였으며, 보다 세밀한 도시유역의 물순환 해석을 위하여 우리나라와 일본에서 적용이 활발한 물리적 기반의 분포형 모형(WEP, SHER, SWMM)의 적용사례를 통하여 국내 도시하천의 물순환 해석에 활용함에 있어서의 실질적인 적용절차 등을 제시하고자 하였다. 한다.호강유역의 급격한 수질개선을 알 수 있다.世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.51-58
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• 2008

Development of a new design guide which is based on empirical-mechanistic concept for pavement design is in action. It is called AASHTO 2002 Design Guide in USA and the KPRP(Korean Pavement Research Project) in Korea. The material characteristic of hot mix asphalt is a key role in the design guide. Therefore it is urgent to get a proper materials database, especially the dynamic modulus of hot mix asphalt. In this research, dynamic modulus test, which is based on aged asphalt binder, has been carried out and proposed the predicted equation of dynamic modulus. Nine different hot mix asphalt with three different asphalt binder have been used for the dynamic modulus test. Short-term aging, which is covers the time for the production of asphalt plant, transportation, lay-down, and compaction, can be simulated at $135^{\circ}C$ with 2 hour curing. Long-term aging has been carried out for a performance period of asphalt pavement. The dynamic modulus of asphalt pavement increases with aging time. As the nominal aggregate size increases, the change of dynamic modulus is not big.