• The Journal of the Acoustical Society of Korea
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• v.36 no.6
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• pp.401-406
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• 2017

This paper presents the performance assessment of several key algorithms conducted for amphibian species sound classification. Firstly, 9 target species including endangered species are defined and a database of their sounds is built. For performance assessment, three feature vectors such as MFCC (Mel Frequency Cepstral Coefficient), RCGCC (Robust Compressive Gammachirp filterbank Cepstral Coefficient), and SPCC (Subspace Projection Cepstral Coefficient), and three classifiers such as GMM(Gaussian Mixture Model), SVM(Support Vector Machine), DBN-DNN(Deep Belief Network - Deep Neural Network) are considered. In addition, i-vector based classification system which is widely used for speaker recognition, is used to assess for this task. Experimental results indicate that, SPCC-SVM achieved the best performance with 98.81 % while other methods also attained good performance with above 90 %.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.60-65
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• 2018

In this paper, a covariance matrix and modulogram are proposed for realizing amphibian sound classification using CNN (Convolutional Neural Network). First of all, a database is established by collecting amphibians sounds including endangered species in natural environment. In order to apply the database to CNN, it is necessary to standardize acoustic signals with different lengths. To standardize the acoustic signals, covariance matrix that gives distribution information and modulogram that contains the information about change over time are extracted and used as input to CNN. The experiment is conducted by varying the number of a convolutional layer and a fully-connected layer. For performance assessment, several conventional methods are considered representing various feature extraction and classification approaches. From the results, it is confirmed that convolutional layer has a greater impact on performance than the fully-connected layer. Also, the performance based on CNN shows attaining the highest recognition rate with 99.07 % among the considered methods.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.22-35
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• 2005

내분비계 장애물질 (Endocrine Disruptors: EDs)이란 ‘내분비 기능에 변화를 일으켜, 생체 또는 그 자손의 건강에 위해한 영향을 미치는 외인성 물질’로서 세계야생생물보호기금 (World Wildife Fund: WWF)의 목록에는 67 여종, 일본 후생성에서는 142 여종의 물질을 내분비계 장애물질로 분류하고 있다. 이렇게 분류된 내분비계장애물질 가운데에는 많은 종류의 농약이 포함되어 있으며, 이들이 자연상태계에 미치는 영향에 대한 많은 보고가 있다. 양서류는 먹이연쇄의 중위포식자로 내분비계 장애물질의 순환 및 생채축적 회로에서 중요한 위치를 갖는다. 또한 농경지나 계류 등에 서식하며 산란하는 습성이 있다. 이러한 서식지는 농약 등에 노출받기 쉬우므로 환경오염평가 대상동물로 중요하다. 본 연구에서는 국내에서 사용되고 있는 제초제, 살충제 등이 양서류 발생에 미치는 영향을 평가하고, 이들 물질에 의한 노출을 평가할 수 있는 biomarker 유전자를 발굴하고자 하였다. 우리나라 전역에 많이 분포하는 무당개구리(Bombina orientalis)의 초기 배아발생 과정에서 이들 농약을 처리하였을 때, 물질의 종류에 따라 정도의 차이는 있으나 농도 의존적으로 배아 및 올챙이의 치사율이 높게 나타났다. 또한 농약은 배아 및 올챙이의 기형을 유발하였다. 기형의 종류는 농약에 따라 서로 상이한 형태로도 나타났으나, 특히 몸통휨 또는 꼬리휨등의 척추골 기형이 많이 나타났다. 환경 위해성 평가 biomarker 유전자로서 골격계 형성에 관여하는 Sox9 유전자를 선택하였다. 무당개구리에서 처음으로 Sox9 유전자를 동정하였으며, 농약을 처리한 실험군에서의 Sox9 유전자의 발현 양상은 대조군에 비하여 높게 나타났다. 본 연구결과 생태계에서 내분비계 장애물질의 위해성 평가를 위해 양서류 초기배아의 치사 및 기형의 정도를 관찰하는 방법이 유효할 것으로 사료된다. 또한 야생동물의 biomarker 유전자를 발굴과 이를 이용한 위해성 평가는 더욱 정밀한 평가법으로 유용할 것이다.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.365-372
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• 1990

For the effort to produce transgenic amphibians, a plasmid DNA sequence (cytoplasmic actin promoter-linked bacterial $\beta$-galactosidase gene) was microinjected into fertilized Xenopus eggs. It appeared that the injection of 20 nl solution containing 1-2 ng of DNA was not toxic, but over 4 ng was toxic to embryonic development. The translational product of $\beta$-gal gene ($\beta$-galactosidase) had enzyme activity in all three germ layers of the embryo. Expression of the injected $\beta$-gal genes was first detected at mid-gastrula stage, and the activity persisted up to stage 43 (feeding tadpole) with decreased level of retention. However, the level of the expression was various among the injected individuals as well as each experiment. That is, $\beta$-galactosidase activities did not appear in all cells, instead a localized distribution pattern. Although other possibilities could not be omitted, this mosaic distribution of gene expression seemed to arise from unequal partition of the injected DNA into each blastomere during early cleavage.

• The Journal of the Acoustical Society of Korea
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• v.39 no.5
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• pp.406-413
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• 2020

In this paper, to improve the classification accuracy of bird and amphibian acoustic sound, we utilize GLU (Gated Linear Unit) and Self-attention that encourages the network to extract important features from data and discriminate relevant important frames from all the input sequences for further performance improvement. To utilize acoustic data, we convert 1-D acoustic data to a log-Mel spectrogram. Subsequently, undesirable component such as background noise in the log-Mel spectrogram is reduced by GLU. Then, we employ the proposed temporal self-attention to improve classification accuracy. The data consist of 6-species of birds, 8-species of amphibians including endangered species in the natural environment. As a result, our proposed method is shown to achieve an accuracy of 91 % with bird data and 93 % with amphibian data. Overall, an improvement of about 6 % ~ 7 % accuracy in performance is achieved compared to the existing algorithms.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Journal of Convergence for Information Technology
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• v.11 no.12
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• pp.168-175
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• 2021

In this study, a transdisciplinary convergence education program was developed to enhance the understanding for classification of reptiles and amphibians in biology education and also to increase AI (Artificial Intelligence) capability by using artificial intelligence education. The main content is to solve the classification of reptiles and amphibians that has been dealt with for a long time in biology education, using a decision tree and ML4K (Machine Learnig for Kids), it was designed for a total of 3 lessons. Experts review was conducted on the developed education program, as a result, the I-CVI(Item Content Validity Index) value was .88~1.00 so that can secure content validity. This education program has the advantage of being able to simultaneously learn about the learning contents of artificial intelligence in informatics and the classification of vertebrates in the biological education. In addition, since it is configured to minimize the cognitive load in the AI using part, it is characterized by the fact that all of any teachers can apply it their lesson easily.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.582-590
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• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.110-126
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• 2024

This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.113-120
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• 2016

We examined whether an artificial levee constructed on prime amphibian habitat influences fragmentation. Four different sites on both sides of a levee in the Civilian Control Zone(CCZ) were probed. Sites 1 and 2 are rice paddies on one side of the levee, and Site 3 is the stream that locates in the same side. All the three sites have water conditions of seasonal variance. On the other side, Site 4 consists of rice paddies with a stable condition of water supply, irrigated through a canal. The research sites were frequented and the frog populations were closely monitored. The investigation identified five species. Pelophylax nigromaculatus was the most frequent (n=295), followed by Hyla japonica (n=220) and Glandirana rugosa (n=124). Three Bufo gargarizans and eight Rana coreana were also found. The amphibians, however, were found to relocate themselves according to water condition to rice paddies or stream only within one side of the levee. Despite having ample sources of water and foods, Site 4 lacked large populations of frogs, even when droughts came. Both the species dominance index and the richness index indicated a more favorable living condition of the one side of the levee (Sites 1 and 2) over the other.