• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.620-624
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• 2004

Optical emission studies were performed to investigate thermal and dynamical properties of a plume produced by laser ablation of a graphite target in a nitrogen atmosphere. Experimental spectra of $C_2(d^3{\Pi}_g{\to}a^3{\Pi}_u$, ${\Delta}_V$=1) and CN ($B^2{\Sigma}^+{\to}X^2{\Sigma}^+,{\Delta}_V=0)$ were simulated to obtain the vibrational and rotational temperatures of the electronically excited species at various laser fluences and distances from the target. The spectroscopic temperatures of both molecules were found to be nearly independent of the laser fluence. The temperature of CN molecules was peaked in the middle of the plume while that of $C_2$decreased with increase in the distance. At a given distance, the temperature of CN molecules was clearly higher than that of $C_2$.

• 생태와환경
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• 제36권1호통권102호
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• pp.9-20
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• 2003

2002년 5월부터 11월까지 한강지류를 대상으로 강우와 기온에 따라 반응하는 분류군과 종을 조사하였다. 윤충류 (Rotifer) 23종, 지각류 (Cladocera) 10종, 요각류(Copepoda) 8종 그리고 원생동물(Protozoa) 1종으로 총42종이 조사되었다. 조사기간 중 5월이 가장 높은 풍부도와 다양한 종이 출현하였다. 조사지에 따라 차이는 있으나 여름 강우로 지각류와 윤충류의 풍부도가 크게 감소하였다. 가장 높은 풍부도를 보였던 윤충류의 5월 우점종은 Brachionus urceolaris, Euclanis dilatata, Lecane luna, Brachionus quadridentatus, Brachionus calyciflorus였다. 8월에는 Monostyla bulla, Conochilus unicornis가 11월에는 Brachionus quadridentatus, Euclanis dilatata, Lecane luna가 다수 출현하였다. 지각류는 5월에 Moina weismanni, Simocephalus vetulus, Scapholebris mucronata, Chydorus sphaericus가 8월에는 소수의 Chydorus sphaericus, Scapholebris mucronata가 11월에는 Chydorus sphaericus, Alona rectangula가 우점을 이루었다. 클러스트링 (nearest neighbour clustering)을 통해 5월과 11월의 조사지에 따른 유형은 유사하였으나 8월은 다른 양상을 보였다.

• 환경영향평가
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• 제21권4호
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• pp.593-607
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• 2012

The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.

• 한국환경복원기술학회지
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• 제26권3호
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• pp.29-42
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• 2023

As the destruction of habitats due to recent development continues, there is also increasing interest in endangered species. Mankyua chejuense is a vulnerable species that is sensitive to changes in population and habitat, and it has recently been upgraded from Endangered Species II to Endangered Species I, requiring significant management efforts. So in this study, we analyzed the potential habitats of Mankyua chejuense using MaxEnt(Maximum Entropy) modeling. We developed three models: one that considered only environmental characteristics, one that considered artificial factors, and one that reflected the habitat of dominant tree species in the overstory. Based on previous studies, we incorporated environmental and human influence factors for the habitats of Mankyua chejuense into spatial information, and we also used the habitat distribution models of dominant tree species, including Ulmus parvifolia, Maclura tricuspidata, and Ligustrum obtusifolium, that have been previously identified as major overstory species of Mankyua chejuense. Our analysis revealed that rock exposure, elevation, slope, forest type, building density, and soil type were the main factors determining the potential habitat of Mankyua chejuense. Differences among the three models were observed in the edges of the habitats due to human influence factors, and results varied depending on the similarity of the habitats of Mankyua chejuense and the dominant tree species in the overstory. The potential habitats of Mankyua chejuense presented in this study include areas where the species could potentially inhabit in addition to existing habitats. Therefore, these results can be used for the conservation and management planning of Mankyua chejuense.

• Journal of applied mathematics & informatics
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• 제24권1_2호
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• pp.49-64
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• 2007

In this paper, we investigate optimal policies for three age-dependent populations in a competition system, which is controlled by fertility. By using Dubovitskii-Milyutin's general theory, the maximum principles are obtained for problems with free terminal states, infinite horizon and target sets, respectively.

• 수산해양기술연구
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• 제34권4호
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• pp.386-392
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• 1998

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권2호
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• pp.114-119
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• 2021

To restore the Gold-spotted pond frog (Pelophylax chosenicus), a Korean endangered frog, 600 captive-reared individuals were reintroduced between August and September 2019 into an aquatic garden in the National Institute of Ecology where P. chosenicus had previously inhabited. After reintroduction, six post-release monitoring sessions were conducted from August 2019 to May 2020. Monitoring was performed using three methods (counting calls, observation, and capture) from sunset to midnight near release sites, eliminating potential threat factors. Snout-vent lengths and body weights of recaptured individuals were measured before they were released immediately. We noted that both snout-vent lengths and body weights of recaptured individuals were slightly higher than those before. The average recapture rate was 4.66%. Reintroduced frogs were recaptured at the last monitoring session conducted in May 2020, indicating that these reintroduced frogs hibernated during the winter successfully. We found that these reintroduced frogs successfully settled after release. This result will be useful for establishing management strategies for endangered frogs in Korea. Particularly, post-release monitoring could be an essential approach in the restoration program of a target species.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권1호
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• pp.54-65
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• 2022

Species distribution models are a useful tool for predicting future distribution and establishing a preemptive response of invasive species. However, few studies considered the possibility of habitat for the aquatic organism and the number of target sites was relatively small compared to the area. Environmental DNA (eDNA) is the emerging tool as the methodology obtaining the bulk of species presence data with high detectability. Thus, this study applied eDNA survey results of Micropterus salmoides and Lepomis macrochirus to species distribution modeling by seasons in the Anyang stream network. Maximum Entropy (MaxEnt) model evaluated that both species extended potential distribution area in October compared to July from 89.1% (12,110,675 m²) to 99.3% (13,625,525 m²) for M. salmoides and 76.6% (10,407,350 m²) to 100% (13,724,225 m²) for L. macrochirus. The prediction value by streams was varied according to species and seasons. Also, models elucidate the significant environmental variables which affect the distribution by seasons and species. Our results identified the potential of eDNA methodology as a way to retrieve species data effectively and use data for building a model.

• 수산해양기술연구
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• 제59권4호
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• pp.290-300
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• 2023

This study aimed to identify the actual catch situation of offshore dredge gear which is newly regulated in the legislation. It's also conducted to identify the species composition, weight of the catch including the target species and incidental catches, and to provide the basic information necessary for the resource management of aquatic organisms caught by offshore dredge. During the investigation period (from September 2022 to May 2023), a total of 61 species appeared in the test operation sea of Boryeong, Chungcheongnam-do and Gunsan, Jeollabuk-do, with 31 species of fishes, 11 species of malacostraca, six species of gastropoda, five species of bivalvia, three species of cephalopoda, three species of asteroidea, one species each of asteroidea and holothuroidea appeared. According to the results of the test operation conducted in September and November 2022, the non-catch season of Atrina (Servatrina) pectinata, 1,203 shellfishes were caught out of 2,979 caught in number, showing a bycatch rate of 59.6%, and by weight, 157.9 kg of shellfish was caught out of the total catch of 448.4 kg, showing a bycatch rate of 64.8%. On the other hand, in February and May 2023, the catch season for Atrina (Servatrina) pectinata, 3,692 fishsells were caught out of the 4,232 catches in total, showing a bycatch rate of 12.8%, and by weight, 1,185.0 kg of shellfish was caught out of the total catch of 1,293.2 kg, showing an 8.3% bycatch rate.

• 한국축산식품학회지
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• 제40권4호
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• pp.628-635
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• 2020

The objective of this study was to detect three non-halal meat products consisted of dog, pork, and rat species in meatball using novel multiplex-PCR with 12S rRNA gene as target sites. A total of 33 self-made meatballs were used, and they were grouped into eleven types of meatball based on meat species origin contained in the meatballs. Each type consisted of three meatballs. Extraction of genomic DNA from the meatballs was used as a DNA template for simplex-, duplex-, and multiplex-PCR processes. The result of simplex-PCR, duplex-PCR, and multiplex-PCR showed that the 12S rRNA primer gene successfully amplified DNA for each species bovine, dog, pig, and rat, which are respectively indicated by 155, 244, 357, and 491 bp of DNA bands. In addition, multiplex-PCR with 12S rRNA gene primers can be uniquely and accurately used for detection bovine, dog, pig, and rat species on beef meatball in one reaction.