• Title/Summary/Keyword: Field observations

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Zooplankton Community as an Indicator for Environmental Assessment of Aquatic Ecosystem: Application of Rotifer Functional Groups for Evaluating Water Quality in Eutrophic Reservoirs (동물플랑크톤 군집의 수생태계 환경 평가 지표 활용: 부영양화 저수지 수질 평가를 위한 윤충류 기능성 그룹의 적용)

  • Oh, Hye-Ji;Chang, Kwang-Hyeon;Seo, Dong-Il;Nam, Gui-Sook;Lee, Eui-Haeng;Jeong, Hyun-Gi;Yoon, Ju-Duk;Oh, Jong Min
    • Journal of Environmental Impact Assessment
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    • v.26 no.6
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    • pp.404-417
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    • 2017
  • In this study, we analyzed response patterns of rotifer community to eutrophic state, and estimated the applicability of rotifer community as an environmental indicator for highly eutrophicated reservoirs. In order to evaluate the relationships among spatial and temporal distributions and the water quality of rotifer community, we selected the Jundae Reservoir and Chodae Reservoir in Chungcheongnam-do, Korea, which are geographically adjacent but have different water quality, particularly in their eutrophic states. For the analyses on their correlations, monthly survey of water quality and rotifer community, was conducted from April to November 2013 in both reservoirs. The rotifer community was divided into different compositions of functional groups as well as species. Functional groups were classified according to the structure and shape of trophi which can represent feeding behavior of rotifer genus. To reflect ecological characteristics of species, body size and habitat preferences were also considered. Species-based composition did not show a consistent tendency with water quality parameters related with eutrophication. On the contrary, functional group composition showed relatively clear group-specific patterns, increasing or decreasing according to the parameters. The results suggest the possible application of rotifer functional group composition as an indicatorforthe lentic systems, especially hyper-eutrophicated reservoirs. The present study can suggest the applicability based on the field observations from the limited time scale and sites, and further studies on feeding behavior of the rotifer functional group and its interactions with environmental variables are necessary for the further application.

The Egg Development of Korean Slender Gudgeon, Squalidus gracilis majimae (Cypriniforms: Cyprinidae) (한국산 긴몰개 (Squalidus gracilis majime, Cyprinidae)의 난발생)

  • Park, Kyung-Seo;Hong, Young-Pyo;Moon, Woon-Ki;Choi, Shin-Suk;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.73-82
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    • 2005
  • This study was conducted, based on the field survey and laboratory observations, to elucidate egg developmental processes and their characteristics of the Korean slender gudgeon, Squalidus gracilis majimae. For the experiments, the mature adults were collected at the Woongcheon-Cheon Stream and Boreung Reservoir located in Boreung City, Chungnam Province and eggs were obtained from the natural spawning area. Morphological characteristics of the egg and embryonic development were summarized as follows: The shape of the fertilized egg was spherical, adhesive and transparent. The fertilized egg was 2.9${\pm}$0.3 mm (n = 30) in mean diameter under water temperature of $26{\pm}1.5^{\circ}C$, light white in color and had no oil droplets. After 20 minutes from the time of fertilization, a blastodisc was formed and divided into two cells at 48 minutes after fertilization. The blastular stage occurred at 5 hours 40 minutes after fertilization and the gastrular stage was detected at 8 hours 41 minutes after fertilization. The beginning of embryo formation was observed at 12 hours 58 minutes after fertilization and optic vesicles and 9 somites were discovered at 17 hours 05 minutes after fertilization. Differentiation of brains and embryo wiggling were observed at 37 hours 27 minutes after fertilization. Heart beating and the formation of melanophores in optic vesicles were detected at 44 hours 46 minutes after fertilization. The formation of pectoral fins and melanophores in the body were discovered at 50 hours 36 minutes after fertilization. Hatching occurred at 57 hours 49 minutes after fertilization. The newly hatched larvae were 3.3${\pm}$0.2 mm (n = 120) in total length. We believe that these results may contribute the species and population conservations under the situation of accelerated water pollution and the decreases of its diversity.

Spawning Behavior and Early Life History of Korea Freshwater Goby (Rhinogobius brunneus) (밀어 (Rhinogobius brunneus)의 산란행동 및 초기생활사)

  • Moon, Woon-Ki;Na, Young-Eun;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.83-94
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    • 2005
  • The objective of the study was to elucidate early life history of Rhinogobius brunneus, based on laboratory observations and field works, along with its courtship and spawning behaviors. The male and female fish matured were sampled for the lab experiments from Gap-Stream, which is one of the tributaries of Geum-River, Korea. The spawning behaviors and courtship of matured adults had a typical pattern; matured males of Rhinogobius brunneus built up spawning nests and had their own territory before the spawning, and the behavior then triggered the egg spawning of female with active courtship. The females attached elliptic egg mass as a single layer, on the stones below the spawning nest. After the spawning, the egg mass was guarded by males only until the hatching. The size of egg fertilized, measured by microscope was about 1.5${\pm}$0.1mm in length and 0.7${\pm}$0.1 mm in the egg's width. According to the lab experiments conducted under four temperature regime, the lapsed time for the hatching was shortened as temperatures increased in the treatments. On the contrary to the hatching time, the average length of newly hatched larvae showed a reverse relation with water temperature. The larvae, considered a final stage of the early life history was about 3.6 mm in total length for water temperature of $18^{\circ}C$, whereas they were between 3.1 mm and 3.2 mm for over $25^{\circ}C$. This indicates that higher water temperature may decrease the growth rate in the early life history. These results may provide valuable information for the population conservation and ecosystem protection under accelerated water pollution and habitat degradations in Korea.

Seasonal Fluctuations of Marine Environment and Phytoplankton Community in the Southern Part of Yeosu, Southern Sea of Korea (여수 남부 협수로 해역의 해양환경과 식물플랑크톤 군집의 계절변동 특성)

  • Noh, Il-Hyeon;Yoon, Yang-Ho;Park, Jong-Sick;Kang, In-Seok;An, Yeong-Kyu;Kim, Seung-Hyun
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.3
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    • pp.151-164
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    • 2010
  • Field observations on the seasonal variations of environmental factors and phytoplankton community were carried out four times at 30 stations in the narrow strait between Yeosu and Dolsan Island of the Korean South Sea from September 2005 to May 2006. The ranges of water temperature, salinity and extinction coefficient in the surface waters were 5.6~26.3, 25.36~33.92 psu and 0.13~2.13, respectively. The water temperature measured higher at Gamak Bay in summer and spring. It measured higher at Yeosuhae Bay in autumn and winter. Salinity showed uniformity of distributions in almost all areas, except for an area near a sewage disposal outlet. Extinction coefficient indicated that the turbidity of Gamak Bay and the area near the sewage disposal outlet were higher than that of the Yeosuhae Bay. In the phytoplankton community were identified a total of 99 species belonging to 51 genera. The species composition showed itself to be various in summer and autumn, but poor in winter and spring with a high ratio of centric diatoms all the year round. Seasonal succession of dominant species were Skeletonema costatum and Chaetoceros curvisetus in summer, Eucampia zodiacus in autumn and winter, and Chaetoceros affinis and Thalassionema nitzschioides inspring. Standing crops of phytoplankton and Chlorophyll $\alpha$ concentration were greatly higher at Gamak Bay in summer with ranges of $0.2{\times}10^4\;cells\;L^{-1}$ to $296{\times}10^4\;L^{-1}$, and $1.94\;L^{-1}$ to $22.12\;L^{-1}$, respectively. From the results of principal component analysis (PCA), the northern part of Dolsan Island was divided into two or three regions from the characteristics of marine environment and phytoplankton community.

Music Activities for Facilitation of Developmental Domains for Children from Age Three to Six (3-6세 유아의 영역별 발달 촉진을 위한 단계별 음악치료교육 활동 연구)

  • Lee, Su yeon
    • Journal of Music and Human Behavior
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    • v.3 no.1
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    • pp.29-62
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    • 2006
  • The early development of an infant is crucial due to the enormous impact it has throughout an infant's life. Therefore, it is important to understand the development process of an infant and provide a high-quality educational environment so that an infant can progress at an innate pace to learn how to exercise, understand, speak, socialize, and empathize as well as having a balanced growth. When educating an infant, joy is a substantial factor in the formation of trust and development of relationship that makes education efficient. Music can be an effective means to offer a fun atmosphere vto the infant in which it stimulates active participation of the infant and development of a variety of dimensions to the infant's development. Also, the purpose of music therapy education is utilizes to plan for the different age groups' level of understanding of music and allow the infant to have a positive experience and develop properly. The purposes of this study are as following: to examine characteristics according to an infant' developmental steps thoroughly, to suggest interventions using music therapy education to stimulate development of an infant, to prove that infants age 3 to 6 obtain the necessary ability and skill through the effective educational therapy through music, and finally to create a music program for educating infants or music therapy. This study has examined theories of the music approach targeting infants age 3 to 6 and made character observations of infant' Motor, Cognition, Communication, Socialization, and Emotions. With the basis of the above theory, the different levels of development has been divided, specific goals has been set up according to the levels, and various music therapy education for infants have been created. The music therapy education activity has been approved by five professionals who are renown in their specific field. They made comments that the development levels were properly divided in the paper. They also commented that the music program is adequate for achieving the goal of each developmental level and it stimulates the different levels of an infant's development. In conclusion, the study reflects that the approach of music therapy education stimulates the different levels of infant development. Music therapists can utilize this music program to help handicapped children identify characteristics of progress and develop at their own ability.

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Spatio-temporal Distributions of Organic Matter in Surface Sediment in the Central Part of the South Sea, Korea (남해 중부해역 표층퇴적물 유기물의 시.공간 분포특성)

  • Noh, Il-Hyeon;Yoon, Yang-Ho;Park, Jong-Sick;Soh, Ho-Young;Kim, Dae-Il
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.4
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    • pp.203-215
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    • 2006
  • Field observations on the spatio-temporal distribution of organic matter of the surface sediment were carried out at 15 stations in the central parts of the South Sea of Korea from April 2002 to January 2003. The range of water temperature and salinity in bottom waters, mud content and water content of surface sediment were $8.06{\sim}23.35^{\circ}C,\;29.20{\sim}34.51\;psu,\;71.2{\sim}99.9%$ and $38.7{\sim}68.9%$, respectively. Measured parameters on the surface sediments of ignition loss (IL), chemical oxygen demand (CODs), phaeopigment, particulate organic carbon (POC) and particulate organic nitrogen (PON) also ranged in $3.9{\sim}l2.5%,\;9.60{\sim}44.05\;mgO_2/g-dry,\;1.58{\sim}29.51\;{\mu}g/g-dry,\;3.12{\sim}13.01\;mgC/g-dry$ and $0.49{\sim}2.00\;mgN/g-dry$, respectively. The spatio-temporal distribution of organic matter demonstrated higher concentrations offshore than at lesions near the coastal line. Higher concentrations occurred in the summer and spring. The results indicated that the origin of organic matter in surface sediments in the central part of the South Sea was autochthonous rather than allocthonous because the organic matter had an average C/N ratio of 6.44 (${\pm}0.51$). However, the composition of autochthonous organic matter was mainly derived from detritus rather than living phytoplankton, which was Indicated by the results of the POC/phaeopigment ratio. A principal component analysis (PCA) indicated that 73.2% of the variability in the data was described by two factors: 1) an 'environmental factor concerning the accumulation of materials (57.3%)' and 2) 'origin of organic matter and the composition by primary production (15.9%)'. The sedimentary environment in the central part of the South Sea was divided into four regions from the factor score of the PCA by the concentrations of organic matter and the composition ratio of organic matters from phytoplankton in surface sediments.

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Avifauna and Management of Breeding Season in Taeanhaean National Park (태안해안국립공원의 번식기 조류상과 관리)

  • Paik, In-Hwan;Jin, Seon-Deok;Yu, Jae-Pyoung;Paek, Woon-Kee
    • Korean Journal of Environment and Ecology
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    • v.24 no.2
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    • pp.139-146
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    • 2010
  • The survey was done in order to find what kinds of birds visit Taeanhaean National Park during breeding season, where we fixed up 10 coastal areas and islands within the National Park. Three groups concurrently performed the field research from 5th to 9th of July in 2009. Total 58 species and 7,323 individuals were recorded in Taeanhaean National Park. 48 species including 6,187 individuals were observed in coastal areas and 33 species including 1,136 individuals in island areas. The most dominant species in the National Park are Larus crassirostris which accounts for 60% of the birds inhabiting there, and they seem to have been bred in the islands near the National Park. The birds observed only around the coastal areas include Anas poecilorhyncha, Fulica atra, Egretta intermedia and the others which consist of 25 species and amount to 318 individuals, and the birds found exclusively in island areas include Phalacrocorax filamentosus, Apus pacificus¸ Locustella pleskei and other birds, which consist of 10 species and the number of those individuals observed was 308. The inhabited islands areas such as Gauido were characterized by high ratio of waterbird population, which seems to be correlated with the factors such as the extent of island, the richness of water resources, and the diversity of habitats. Based on the data collected during the research and other data from the previous observations, the kinds of dominant species remain nearly unchanged. And in spite of the oil spill accident in 2007, the increase in the number of waterbirds compared to 2004 may be the evidence that the area is recovering from the environmental pollution. At present, the tidal power plants are being built or scheduled to be built and large-scale reclamation is also under way. What is worse, those areas are seeing the increase of pension construction, which is likely to be the potential cause of damage and disturbance against some key habitats for the waterbirds. Therefore, it is a major priority that we build the bird information system to efficiently manage the knowledge-based asset collected from bird-watching groups and to better monitor the areas that need enhanced database through which the National Park can be appropriately administered.

Timing of Diapause Induction and Number of Generations of Helicoverpa armigera (Hüber) (Lepidoptera: Noctuidae) in Suwon, Korea (수원지방에서 왕담배나방 (밤나방과) 휴면 유기시기와 연간 발생 세대)

  • Jung, Jin Kyo;Seo, Bo Yoon;Park, Chang-Gyu;Ahn, Seung-Joon;Kim, Ju Il;Cho, Jum Rae
    • Korean journal of applied entomology
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    • v.54 no.4
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    • pp.383-392
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    • 2015
  • We investigated the induction of pupal diapause and number of generation for H. armigera using outdoor rearing and sex pheromone trapping in Suwon, Korea. Over-wintering pupae were induced when neonate larvae were reared in the outdoors from late Aug. to early Oct. in 2013 and 2014. H. armigera adults emerged from late May to early Jun. for 2013 colonies and from late May to late Jun. for 2014 colonies. The colonies placed after mid September produced only diapause pupae, to show environmental conditions that day-lengths on the rearing start date were 11 h 49 min~12 h 24 min, and mean temperatures before pupation were $14.8{\sim}20.7^{\circ}C$. Summer diapause was not observed in all colonies. The peak occurrence of H. armigera adults from sex pheromone trap in Suwon and Hwaseong were pooled and showed four generations (1st: from late Apr. to mid Jun., 2nd: from mid Jun. to late Jul., 3rd: from mid Jul. to late Aug., 4th: from late Aug. to mid Oct.). A degree-day model for development of H. armigera developed by Mironidis and Savopoulou-Soultani (2008) was used to validate the number of generation from field observations using pheromone traps. The 3rd and over-wintering generations were mainly overlapped. It was decided that H. armigera has one over-wintering and three complete generations in a year, and diapause is induced from offsprings of the 3rd and 4th generations adults. It is expected that larvae of the 1st and 2nd generations give a damage to ear zone in maize fields in which have been planted during April.

A Study on Damage factor Analysis of Slope Anchor based on 3D Numerical Model Combining UAS Image and Terrestrial LiDAR (UAS 영상 및 지상 LiDAR 조합한 3D 수치모형 기반 비탈면 앵커의 손상인자 분석에 관한 연구)

  • Lee, Chul-Hee;Lee, Jong-Hyun;Kim, Dal-Joo;Kang, Joon-Oh;Kwon, Young-Hun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.7
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    • pp.5-24
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    • 2022
  • The current performance evaluation of slope anchors qualitatively determines the physical bonding between the anchor head and ground as well as cracks or breakage of the anchor head. However, such performance evaluation does not measure these primary factors quantitatively. Therefore, the time-dependent management of the anchors is almost impossible. This study is an evaluation of the 3D numerical model by SfM which combines UAS images with terrestrial LiDAR to collect numerical data on the damage factors. It also utilizes the data for the quantitative maintenance of the anchor system once it is installed on slopes. The UAS 3D model, which often shows relatively low precision in the z-coordinate for vertical objects such as slopes, is combined with terrestrial LiDAR scan data to improve the accuracy of the z-coordinate measurement. After validating the system, a field test is conducted with ten anchors installed on a slope with arbitrarily damaged heads. The damages (such as cracks, breakages, and rotational displacements) are detected and numerically evaluated through the orthogonal projection of the measurement system. The results show that the introduced system at the resolution of 8K can detect cracks less than 0.3 mm in any aperture with an error range of 0.05 mm. Also, the system can successfully detect the volume of the damaged part, showing that the maximum damage area of the anchor head was within 3% of the original design guideline. Originally, the ground adhesion to the anchor head, where the z-coordinate is highly relevant, was almost impossible to measure with the UAS 3D numerical model alone because of its blind spots. However, by applying the combined system, elevation differences between the anchor bottom and the irregular ground surface was identified so that the average value at 20 various locations was calculated for the ground adhesion. Additionally, rotation angle and displacement of the anchor head less than 1" were detected. From the observations, the validity of the 3D numerical model can obtain quantitative data on anchor damage. Such data collection can potentially create a database that could be used as a fundamental resource for quantitative anchor damage evaluation in the future.

Ultimate Reality in Daesoon Thought as Viewed from Perennial Philosophy (영원철학(The Perennial Philosophy)으로 본 대순사상의 궁극적 실재)

  • Heo, Hoon
    • Journal of the Daesoon Academy of Sciences
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    • v.32
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    • pp.137-173
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    • 2019
  • Modern scientists are trying to find the basic unit of order, fractal geometry, in the complex systems of the universe. Fractal is a term often used in mathematics or physics, it is appropriate as a principle to explain why some models of ultimate reality are represented as multifaceted. Fractals are already widely used in the field of computer graphics and as a commercial principle in the world of science. In this paper, using observations from fractal geometry, I present the embodiment of ultimate reality as understood in Daesoon Thought. There are various models of ultimate reality such as Dao (道, the way), Sangje (上帝, supreme god), Sinmyeong (神明, Gods), Mugeuk (無極, limitlessness), Taegeuk (太極, the Great Ultimate), and Cheonji (天地, heaven and earth) all of which exist in Daesoon Thought, and these concepts are mutually interrelated. In other words, by revealing the fact that ultimate reality is embodied within fractal geometry, it can be shown that concordance and transformation of various models of ultimate reality are supported by modern science. But when the major religions of the world were divided along lines of personality (personal gods) and non-personality (impersonal deities), most religions came to assume that ultimate reality was either transcendental or personal, and they could not postulate a relationship between God and humanity as Yin Yang (陰陽) fractals (Holon). In addition, religions, which assume ultimate reality as an intrinsic and impersonal being, are somewhat different in terms of their degree of Holon realization - all parts and whole restitution. Daesoon Thought most directly states that gods (deities) and human beings are in a relationship of Yin Yang fractals. In essence, "deities are Yin, and humanity is Yang" and furthermore, "human beings are divine beings." Additionally, in the Daesoon Thought, these models of ultimate reality are presented through various concepts from various viewpoints, and they are revealed as mutually interrelated concepts. As such, point of view regarding the universe wherein Holarchy becomes a models in a key idea within perennial philosophy. According to a universalized view of religious phenomena, perennial philosophy was adopted by the world's great spiritual teachers, thinkers, philosophers, and scientists. From this viewpoint, when ultimate reality coincides, human beings and God are no longer different. In other words, the veracity of the theory of ultimate reality that has appeared in Daesoon Thought can find support in both modern science and perennial philosophy.