• Korean journal of applied entomology
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• v.59 no.4
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• pp.333-339
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• 2020

Pheromone-based techniques are becoming a viable strategy of insect pest management as facilitated by the exponential increase in numbers of pheromone identifications from many insect pests. This is the report on the efficacy of pheromone-mediated chemical communication disruption (PCD) technique against the Korean population of smaller clearwing moths, Synanthedon tenuis (Butler) (Lepidoptera: Sesiidae) using its female sex pheromone component, (Z, Z)-3, 13-octadecadien-1-ol. The PCD trials were carried out four times during 2016 and 2017 in persimmon orchards located at Suncheon and Jinju Cities in Korea, and the PCD efficacy was expressed as the mean differences in the seasonal catches of S. tenuis males in the PCD and control plots. The seasonal male moth catches in monitoring traps installed in the PCD plots were significantly lower as compared with those installed in the control plots. Consequently, the PCD efficacy in the experimental orchards ranged from 95.2-100% with an average efficacy of 98.8 ± 1.2%, revealing a future possibility of pheromone-based management of S. tenuis.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.103-113
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• 2021

This study was investigated to find out the distribution of flora and remarkable plants and factors and management measures for influx of wild disturbed plants in the Damyang area of Mudeungsan National Park. The field survey was carried out 8 times from May 2019 to October 2020. First of all, in the Damyang area of Mudeungsan National Park, a total of 603 taxa in 107 families, 349 genera, 531 species, 57 varieties, 5 subspecies and 10 forms. This result was found to be about 12.33% of the total 4,881 taxa of vascular plants in Korea. In addition, Rare plants were classified as 15 taxa. Floristic special and Korean endemic plants were identified as 85 taxa and 13 taxa, respectively. Lastly, the naturalized plants that appeared in the Damyang area of Mudeungsan National Park were observed in 45 taxa with 45 species of 16 families and 36 genera. Moreover the naturalization rate was 7.46% and the urbanization index was calculated to be 14.01%. The wild disturbed plants were found in a total of 4 taxa. Especially, a sheep sorrel(Rumex acetosella) was focused on managing for physica and biological control at Sinseondae Eoksaepyungjeon.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.70-82
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• 2023

Recently, Korean government has introduced Multi Metric Indices (MMI) using various biocommunity information for aquatic ecosystem monitoring and ecosystem health assessment at the national level. MMI is a key tool in national ecosystem health assessment programs. The MMI consists of indices that respond to different target environmental factors, including environmental disturbance (e.g. nutrients, hydrological and hydraulic situation of site etc.). We used zooplankton community information collected from Korean lakes to estimate the availability of candidate zooplankton MMI indices that can be used to assess lake ecosystem health. First, we modified the candidate indices proposed by the U.S. EPA to suit Korean conditions. The modified indices were subjected to individual index suitability analysis, correlation analysis with environmental variables, and redundancy analysis among indices, and 19 indices were finally selected. Taxonomic diversity was suggested to be an important indicator for all three taxonomic groups (cladoceran, copepod, rotifer), on the other hand, the indices using biomass for large cladocerans and copepods, while the indices using abundance were suggested for small cladocerans and rotifers.

• KDI Journal of Economic Policy
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• v.25 no.2
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• pp.137-170
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• 2003

Despite the great success of the derivatives market, several concerns were expressed regarding the additional volatilitystemming from program trading during the expiration of derivatives. This paper examines the impact of the expiration of the KOSPI 200 index derivatives on cash market of Korea Stock Exchange(KSE). The KOSPI 200 index derivatives market has a unique settlement price determination process. The settlement price for the expiration of derivatives is determined by call auction during the last 10 minutes after the trades for matured derivatives are finalized. We analyze typical expiration day effects such as price, volatility, and volume effects. With high frequency data, we find that there are strong expiration day effects in the KSE and try to interpret the results with the unique settlement procedures of the KOSPI 200 cash and derivatives markets.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.138.1-138.1
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• 2012

자기 구름은 자기 구조를 가지고 방출된 CME로 지구 자기장에 영향을 주는 중요한 원인 중 하나이다. 지구 자기장의 교란으로 발생하는 지자기 활동은 K 지수로 표현되는데 우주기상을 연구하는데 기본 자료로 활용된다. 따라서 자기 구름은 우주기상을 연구하는데 필요한 자료라 할 수 있다. 기존에 Lynch et al.(2005), Huttunen et al.(2005), Lepping et al.(2006), Feng et al.(2007) 등이 만든 자기 구름 리스트가 있지만 자기 구름에 적합하지 않는 이벤트가 적지 않게 포함되어 있어 이벤트를 지자기 활동 연구에 활용하기에 어려움이 있었다. 이 연구에서는 우리만의 자기 구름 기준을 정하고, 이 기준과 실린더 모델을 이용해 새로운 자기 구름 리스트를 완성하였다. 우리가 정한 자기 구름 기준은 (1)자기장의 벡터 성분이 천천히 회전하고 (2)자기장의 세기가 평균보다 세며 (3)자기 구름 지속시간이 7시간보다 짧은 이벤트도 모두 포함하는 것이다. ACE위성과 WIND 위성이 2000년에 관측한 행성간 자기장 자료에 우리의 자기 구름 기준을 적용하여 자기 구름 이벤트 후보를 선정하였고, 마루바시 박사가 만든 실린더 모델을 자기 구름 이벤트 후보에 적용하여 자기 구름 이벤트를 최종 선정하였다. 이렇게 선정된 2000년도 자기 구름 이벤트는 총 63개이고 이를 리스트로 작성하였다. 우리가 만든 자기 구름 이벤트 리스트는 CME와 K 지수 등 지자기 활동 연구에 활용되고 있다.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.31-45
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• 2020

The biological indices based on the community structure with species richness and/or abundance are commonly used to assess aquatic ecosystem health. Meanwhile, recently functional traits-based approach is considered in ecosystem health assessment to reflect ecosystem functioning. In this study, we developed a database of biological traits for 136 taxa consisting of major stream insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera, and Odonata) collected at Korean streams on the nationwide scale. In addition, we obtained environmental variables in five categories (geography, climate, land use, hydrology and physicochemistry) measured at each sampling site. We evaluated the relationships between community indices based on taxonomic diversity and functional diversity estimated from biological traits. We classified sampling sites based on similarities of their environmental variables and evaluated relations between clusters of sampling sites and diversity indices and biological traits. Our results showed that functional diversity was highly correlated with Shannon diversity index and species richness. The six clusters of sampling sites defined by a hierarchical cluster analysis reflected differences of their environmental variables. Samples in cluster 1 were mostly from high altitude areas, whereas samples in cluster 6 were from lowland areas. Non-metric multidimensional scaling (NMDS) displayed similar patterns with cluster analysis and presented variation of taxonomic diversity and functional diversity. Based on NMDS and community-weighted mean trait value matrix, species in clusters 1-3 displayed the resistance strategy in the life history strategy to the environmental variables whereas species in clusters 4-6 presented the resilience strategy. These results suggest that functional diversity can complement the biological monitoring assessment based on taxonomic diversity and can be used as biological monitoring assessment tool reflecting changes of ecosystem functioning responding to environmental changes.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.251-270
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• 2014

The purpose of this study is to offer the basic data and method for assessing the naturaliness of temple environment by applying the ecological index of plant to quantitatively and objectively assess the flora and to understand the flora distributed in major temple forest. The ecological index of plant was based in the surveyed flora. The whole flora were summarized as 535 taxa including 103 families, 310 genera, 426 species, 5 subspecies, 82 varieties and 22 forms. And, the numbers of taxa in the Beopheungsa were 267 taxa, 314 taxa of the Daeseungsa and 296 taxa of the Seongjusa. The rare plants were 9 taxa including Aristolochia contorta, Viola albida, Arisaema heterophyllumand so forth, and the Korean endemic plants were 11 taxa including Clematis trichotoma, Stewartia pseudocamellia, Vicia chosenensis and so forth. The specific plants by floristic region were 51 taxa including Wistaria floribunda, Celtis aurantiaca, Angelica gigas and so forth, and the pteridophyta were 26 taxa including Osmunda japonica, Polystichum braunii, Onoclea orientalis and so forth. The naturalized plants were 35 taxa including Fallopia dumetorum, Conyza canadensis, Xanthium strumarium and so forth, the invasive alien plants were 3 taxa including Ambrosia artemisiifolia, Aster pilosus and Eupatorium rugosum. In the results of analysing the ecological index of plant in whole temple forests, RI(Rare Index) was 1.7%, 2.1% of EI(Endemic Index), 9.5% of SI(Specific Index), 1.2 of PI(Pteridophyta Index) and 6.5% of NI(Naturalized Index) in narrow sense. In broad sense, FI(Flora Index) was 11.0%, 1.5% of RI, 3.4% of EI, 4.8% of SI, 10.1% of PI, 10.9% of UI(Urbanized Index) and 25.0% of DI(Disturbed Index). The FI of the Daeseungsa was the highest among the three temple forests. In narrow sense, the RI, SI, NI and DI of the Beopheungsa was high, the seongjusa was higher the EI and SI. In broad sense, the RI and SI of the Beopheungsa, the EI, SI and PI of the Seongjusa, the UI is high in the Daeseungsa. In future, if we will analyze ecological index of plant in other temple forests, we will offer the help to establishing the plan of conservation and restoration on ecosystem in whole temple forests.Environmental Specimen Banks (ESBs) are playing pivotal role in monitoring the effect of environmental pollution on the ecosystem based on the retrospective analysis of the representative samples collected regularly and stored in cryogenic condition.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.327-336
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• 2007

This study assessed ecological health using a multi-metric fish model from 15 sites in the headwater watershed of southern Han River during June${\sim}$August 1999 and then compared the health with conventional community diversity index to figure out differences between health and diversity index. For the analysis, we adopted 10 metric IBI model for regional applications. During this survey, total number of species sampled were 24 (6 families) and varied depending on magnitude of ecological disturbance and stream order. In the mountainous streams, mean proportion of sensitive and insectivore species was composed of 91% and 56%, respectively, indicating a potential healthy conditions. However, tolerant species with 66% and omnivore species with 76% were sampled from the 2nd order stream, which was shown deterioration in the physical habitat quality. In the overall watershed, mean IBI value was 38, judging as "fair" condition by the health criteria. Values of Individual IBI were closely associated with stream order and this pattern was similar to other mountainous streams showing low chemical pollutions and disturbance. Our comparison between IBI and diversity index over the stream order showed a distinct difference; Shannon-Weaver diversity index overestimated the actual community conditions and the variation range in the 2nd order stream was greater in the diversity index. Overall data suggest that the multi-metric approach may to a useful tool for stream ecosystem management and the conventional diversity index may not effective unless the stream order is considered for the stream evaluation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.649-654
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• 2007

Eavesdropping prevention performance is evaluated on a commercial window shaker, which is used to prevent a glass window from eavesdropping. Speech transmission index (STI) is introduced in order to estimate quantitatively the speech intelligibility of the sound detected on the glass window. Objective test by IEC standard using modulation transfer function (MTF) is performed to determine STI. Using Maximum Length Sequency (MLS) signal as a sound source, MTF is measured by accelerometers and laser doppler vibrometer. STI under different level of disturbing wave are compared to confirm the disturbing effect on the speech intelligibility.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.551-556
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• 2008

Possibility of the remote eavesdropping through window glass is investigated using a laser sensor. Various thicknesses and types of glass windows are excited by maximum length sequency (MLS) signal and the vibration sound is detected by a laser doppler vibrometer. Intelligibility of the detected sound is evaluated using the speech transmission index (STI), which is based on the modulation transfer function (MTF). In order to identify the disturbing effect, different level of disturbing wave is generated by an outside speaker and a window shaker attached on the glass window. On the different thickness of glass windows, decrease effect of the speech intelligibility is analysed.