• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.79-85
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• 2007

From the surveys of 2005 and 2006 in Korea, Trissolicus nigripedius was found in four locations, i.e., Andong, Miryang, Namhae, and Suwon, and one of the major egg parasitoids of Dolycoris baccarum. T. nigripedius was also found to parasitize two other soybean bugs, Riptortus clavatus and Piezodous hybneri, from the field collection in 2005. Host acceptance behaviors of T. nigripedius consisting of drumming, oviposition, and marking were observed and compared on five species of soybean bugs. T. nigripedius showed the complete host acceptance behaviors on the eggs of D. baccarum, P. hybneri, and Halyomorpha halys. But T. nigripedius emerged only from the eggs of D. baccarum (96%) and P. hybneri (75%) after 24 hours of exposure. T. nigripedius did not mark on the eggs of R. clavatus and Nezara antennata during the observation of behavior, hence no egg deposition was made. However, T. nigripedius parasitized 20% and killed 30% of the eggs of R. clavatus when 24 hours were given for parasitization. T. nigripedius would be a potential biological control agent of D. baccarum and P. hybneri with ability of giving additional mortality on R. clavatus in soybean field.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.288-295
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• 1998

Egg production of Acartia steueri was estimated in llkwang Bay, located in the southeastern coast of Korea. The equation, combining fecundity, temperature and chlorophyll a, obtained under the laboratory experiments, was applied to the in situ temperature and chlorophyll a for the estimation of field egg production. Mean egg size was $80.52{\mu}m$. Prosome length of adult females was not correlated with egg size. Egg production of field population ranged from 0.32 to $63.32{\mu}gC\;m^{-3}d^{-1}$ with a mean of $13.33{\mu}gC\;m^{-3}d^{-1}$, which were equivalent to $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$ and $296.1\;eggs\;m^{-3}d^{-1}$, respectively. Fecundity of adult females ranged from 5.4 to $12.5\;eggs\;female^{-1}d{-1}$ with a mean of $8\;eggs\;female^{-1}d^{-1}$. Specific egg production rates ranged from 0.028 to 0.117 $d^{-1}$ with a mean of 0.064 $d^{-1}$. Considering the egg Production ($\%$ female body carbon) as a function of temperature and chlorophlrll a concentration, our results showed rather low fecundity, which might be underestimated. Probable cannibalism of egg by the adults were thought to be pan of the reason for this low estimated fecundity.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.545-550
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• 2006

Ten supernormal clutches of little terns Sterna albifrons and seven clutches having mixed eggs by little terns and kentish plovers Charadrius alexandrinus were recorded during the breeding seasons of 2003$\sim$2005 at Ganwol lake, Hongsung-gun, Chungcheongnam-do, Korea. The frequency of egg retrieval by Little Terns was higher after the second egg laying regardless of the clutch size and incubation stage. The frequency of egg retrieval was high at all incubation stage. When experimental eggs were placed within 15 cm from the nests, the percentage of egg retrieval was highest (almost 100%). However the percentage dropped rapidly over 35$\sim$55 cm range and finally to zero at 60 cm distance. Little terns retrieved all kinds of eggs set near their nests regardless of its kind or size. This study suggests that egg retrieval by little terns may be a source of the nest with supernormal and mixed egg clutch observed in this species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.3
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• pp.108-116
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• 2006

To investigate the factors controlling the spring population of Acartia hongi, egg production, hatching time of egg and predation pressure were measured. Egg production was maintained the superior position between winter and spring. Egg production was positively correlated with not only water temperature when water temperature was below $7^{\circ}C$ but also chlorophyll-a concentration when it was from $7^{\circ}C$ to $21^{\circ}C$. A regressive equation of development time$(D_e,\;day)$ of eggs derived from water temperature$(T,\;^{\circ}C)$ was obtained as $D_e=18.9(T-0.4)^{-1.0}$, showing longer development time at water temperature below $5^{\circ}C$. In Cross Correlation Analysis(CCA) to examine the time-lag relationship among abundances of developmental stages of A. hongi, egg production rate calculated by multiplying population egg production rate by hatching time showed more significant correlation with nauplii abundance than population egg production rate. Therefore, it suggests that hatching time is also recognized by a factor controlling formation of population and especially, in winter, high abundance of egg derived from high daily egg production rate and delayed hatch by low water temperature become the origin of initial spring population of nauplii. Egg predation by Noctiluca scintillans, suggesting a negative factor in formation of A. hongi spring population, was observed. During spring, A. hongi eggs were found in $2.9\sim21.1%$ of individuals of N. scintillans. It was deduced that $1.2\sim49.5%$ of the eggs produced by A. hongi was preyed on by N. scintillans. In conclusion, the factors controlling spring population of A. hongi were regarded as high egg production by winter generation, the delayed development time of egg by low temperature, and egg predation of N. scintillans.

• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.195-211
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• 2005

The Kusandong Tuff, known as a representative key bed in the Cretaceous Gyeongsang Basin, is a crystal-rich tuff of pyroclastic flow and surge origin. It is 1-4 m thick and laterally extends for more than 200 km intercalated in the upper part of the Hayang Croup. Observations and analyses of the feldspar crystals in the tuff, using polarizing microscopes, EPMA, and BSE images, reveal that the plagioclase crystals in the tuff were completely albitized (>$97\%$ Ab) whereas those in the southernmost localities where the tuff is rich in fine ash matrix are unaltered or partly albitized. K-feldspars are partly albitized at all localities, irrespective of the matrix content of the tuff, Perthitic textures, chessboard twinning, albitization along micro-fractures and cleavages, and the relationship between matrix content and the degree of albitization suggest that feldspars in the Kusandong Tuff were albitized by Na-rich fluid after burial. Albitization is interpreted to start preferentially along micro-fractures and cleavages and be hampered in matrix-rich tuffs with a low permeability. Original composition of the plagioclases in the Kusandong Tuff is also interpreted to have ranged between oligoclase and andesine ($Ab_{62.5}-Ab_{83.3}$) before the albitization.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.138-144
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• 2023

The main factor of biodiversity decline in major biological populations around the world is invasion of alien species. To protect native species, it is necessary to manage alien species. Recently, to eradicate ecosystem disturbance caused by alien species in Korea, many efforts have been made to capture individuals using nets and purchase captured individuals. However, there is no standard for classifying species due to the form of nest site or external characteristics of eggs of freshwater turtles. Thus, Mauremys reevesii eggs might be discarded due to mistaking as eggs of alien turtles. Based on more data, this study aims to compare and analyze external differences among eggs of Trachemys scripta elegans, Pseudemys concinna, and M. reevesii and use them as reference materials in the process of eradicating alien turtles. This study measured characteristics of eggs of the three turtle species. As a result of comparison, all variables of external characteristics of alien turtles and M. reevesii eggs showed significant differences. The shape of egg was also different, with eggs of T. scripta elegans and P. concinna showing a bicone shape and those of M. reevesii showing an ellipsoid shape. In conclusion, based on results of previous studies and the present study, eggs of M. reevesii, T. scripta elegans, and P. concinna are different in shape and structure. Thus, it is possible to distinguish between M. reevesii and invasive alien turtle using their eggs.

• KOREAN POULTRY JOURNAL
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• v.37 no.9 s.431
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• pp.130-131
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• 2005

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.143-147
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• 2024

This study aimed to determine the egg-hatching period of boreal digging frogs, Kaloula borealis, and investigate whether the incubation temperature affects the hatching period. In this study, the egg hatching was recorded based on the appearance of the tadpole. The results of this study showed that all the eggs hatched within 48 hours after spawning, with 28.1% (±10.8, n=52) hatching within 24 hours and 99.9% (±0.23, n=49) within 48 hours after spawning. The mean hatching rate of tadpoles showed significant differences depending on the difference in water temperature. The mean hatching rate between 15 and 24 hours after spawning was higher at a water temperature of 21.1 (±0.2) ℃ than at 24.1 (±0.2) ℃. The results suggest rapid hatching occurs at relatively low water temperatures because the spawning habits that spawn eggs in temporary ponds or puddles in the rainy season require rapid hatching before the puddles dry out. The results of this study are helpful for understanding the most suitable temperature conditions for the incubation of eggs of the endangered species, boreal digging frog.

• 주택과사람들
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• s.207
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• pp.102-103
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• 2007

사업 시행 시 사업 부지의 100분의 90을 차지하는 면적을 확보했지만, 그 나머지를 확보하지 못해 법적 소송으로까지 이어지는 경우가 많다. 속칭 '알박기'에 대한 법적 제재가 이뤄지고 있는 가운데, 10년 이상 토지를 보유한 자에게도 매도 청구권을 행사하도록 하는 주택법 개정안이 실시될 예정이다. '계약의 자유'라는 측면에서 속칭 '알박기'의 법적 규정 범위와 주택법 개정안의 관련 내용을 살펴보았다.

• 정보화사회
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• s.115
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• pp.23-35
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• 1997

컴퓨팅 환경은 컴퓨터 역사와 더불어 지속적으로 변해 왔다. 현재에서의 그 변화는 인터넷과 인트라넷이라고 볼 수 있다. 본 기사에서는 차세대 컴퓨팅환경으로서의 인트라넷에 관하여 알아 본다, 먼저, 컴퓨팅 모델의 변화에 관하여 알아 보고, 인트라넷의 개요, 인트라넷시스템 통합 그리고 인트라넷의 확장 시스템 및 향후 인트라넷의 전망에 관하여 알아 본다. 특히 향후 인트라넷 확장 시스템으로서의 엑스트라넷, 인트라넷 ERP, 엑스트라넷을 통한 CALS/EC 시스템으로의 이행에 관하여 알아본다.