• 한국산림과학회지
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• 제98권2호
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• pp.197-202
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• 2009

We studied bird communities among in rice field (46 plots), short grallland (47plot), and tall grass mixed shrub (21 plots) during dry season, January 2007 in Boeung Prek Lapouv (BPL) Important Bird Area, Mekong Delta, Cambodia using the point-count method. Water depth, vegetation height and shrub density were significantly different among the three study areas. We recorded, 60 bird species, of which 13 differed significantly among habitats. Landbirds such as Grey-breasted Prinia (Prinia hodgsonii) and Oliver-black Sunbird (Nectarinia jugularis) were much more abundant (P<0.0001) in the tall grass mixed shrub, whereas the Sarus Crane (Grus antigone), herons and egrets were more abundant in the short grass (P<0.05). Bird species richness and species abundances were not significantly different among habitats. Bird species diversity (H') was higher in grasslands than in rice fields. Mosaic habitat matrix, such as rice field, short grass, and tall grass mixed shrub, should be maintained for the extend and quality of wetlands, and the prevailing human-land use patterns, appear adequate and conductive for waterbirds in the Mekong Delta, Cambodia.

• 한국습지학회지
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• 제7권4호
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• pp.89-95
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• 2005

Understanding of routes of migratory birds are important subject for conservation of avifauna. Korea Demilitarized zone (DMZ) is considered as one of the most important stopover for migratory birds that pass in the Korean peninsula. This region has been known internationally as an excellent nature preservation areas since 1953. Rare and endangered animal species such as leopards (Pathera pardus) and Siberian tigers (Panthera tigris) have increased in population. Furthermore this areas provide home for endangered migratory birds including white-naped (Grus vipio) and red-crowned cranes (G. japonensis). Recent satellite-tracked crane species has shown the importance and linkages between a small number of habitat sites in DMZ. White-naped cranes were satellite tracked 9 individuals spent 27-78% of their time in Panmunjum and 10-75% in Cheolwon. This signifies the rich feeding sites with relatively little disturbance thus making the DMZ extremely valuable as a stopover.

• 기술혁신연구
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• 제14권3호
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• pp.117-154
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• 2006

This research examines performance evaluatees' opinions regarding the current institutional performance evaluation systems of Government S&T Research Institutes (GRIs). Under the current evaluation systems, twenty GRIs are grouped into three Research Groups and each Group has its own evaluation systems. One problem of the current institutional evaluation systems is that the systems cannot reflect individual GRIs' characteristics. The following methods are used. First, based on four perspectives of Kaplan & Norton(1992)'s Balanced Scorecard(BSC) model, six perspectives appropriate to GRUs' characteristics are derived. Second, experts classify current performance evaluation measures into the six perspectives. This enables different evaluation systems of three GRI Research Groups to be compared under the same evaluation measures. Third, GRIs' evaluatees are asked to allocate appropriate weights on the performance measures. Evaluatees' weights of a GRI are compared with average weights of the related Group. Finally in every BSC's perspective, GRIs that have extraordinarily over-scored or under-scored weights are analyzed in terms of GRIs' missions, customers, capability of human resources, etc. In the Basic Research Group, the Korea Basic Science Institute is deviated in the financial perspective and the strategic direction perspectives. In the Public Research Group, Korea Institute of Construction Technology is significantly different from other GRIs in three perspectives. Five out of eight GRIs in the Industrial Research Group, GRIs are significantly different each other in several perspectives. It could be concluded that the current institutional evaluation systems are least appropriate in measuring performance of the GRIs of the Industrial Research Group.

• 한국기계가공학회지
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• 제19권12호
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• pp.21-27
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• 2020

Lithium-ion batteries are the heart of energy-storing devices and electric vehicles. Owing to their superior qualities, such as high capacity and energy efficiency, they have become quite popular, resulting in an increased demand for failure/damage prevention and useable life maximization. To prevent failure in Lithium-ion batteries, improve their reliability, and ensure productivity, prognosticative measures such as condition monitoring through sensors, condition assessment for failure detection, and remaining useful life prediction through data-driven prognostics and health management approaches have become important topics for research. In this study, the residual useful life of Lithium-ion batteries was predicted using two efficient artificial recurrent neural networks-ong short-term memory (LSTM) and gated recurrent unit (GRU). The proposed approaches were compared for prognostics accuracy and cost-efficiency. It was determined that LSTM showed slightly higher accuracy, whereas GRUs have a computational advantage.

• 한국멀티미디어학회논문지
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• 제25권9호
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• pp.1257-1265
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• 2022

Recognition of sign language is challenging due to the occlusion of hands, accuracy of hand gestures, and high computational costs. In recent years, deep learning techniques have made significant advances in this field. Although these methods are larger and more complex, they cannot manage long-term sequential data and lack the ability to capture useful information through efficient information processing with faster convergence. In order to overcome these challenges, we propose a word-level sign language recognition (SLR) system that combines a real-time human pose detection library with the minimized version of the gated recurrent unit (GRU) model. Each gate unit is optimized by discarding the depth-weighted reset gate in GRU cells and considering only current input. Furthermore, we use sigmoid rather than hyperbolic tangent activation in standard GRUs due to performance loss associated with the former in deeper networks. Experimental results demonstrate that our pose-based optimized GRU (Pose-OGRU) outperforms the standard GRU model in terms of prediction accuracy, convergency, and information processing capability.

• International Journal of Computer Science & Network Security
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• 제23권9호
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• pp.47-54
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• 2023

For Bengali music emotion classification, deep learning models, particularly CNN and RNN are frequently used. But previous researches had the flaws of low accuracy and overfitting problem. In this research, attention-based Conv1D and BiGRU model is designed for music emotion classification and comparative experimentation shows that the proposed model is classifying emotions more accurate. We have proposed a Conv1D and Bi-GRU with the attention-based model for emotion classification of our Bengali music dataset. The model integrates attention-based. Wav preprocessing makes use of MFCCs. To reduce the dimensionality of the feature space, contextual features were extracted from two Conv1D layers. In order to solve the overfitting problems, dropouts are utilized. Two bidirectional GRUs networks are used to update previous and future emotion representation of the output from the Conv1D layers. Two BiGRU layers are conntected to an attention mechanism to give various MFCC feature vectors more attention. Moreover, the attention mechanism has increased the accuracy of the proposed classification model. The vector is finally classified into four emotion classes: Angry, Happy, Relax, Sad; using a dense, fully connected layer with softmax activation. The proposed Conv1D+BiGRU+Attention model is efficient at classifying emotions in the Bengali music dataset than baseline methods. For our Bengali music dataset, the performance of our proposed model is 95%.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제4권2호
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• pp.79-85
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• 2023

The Tibetan Plateau is home to the only alpine crane species, the black-necked crane (Grus nigricollis). Conservation efforts are severely hampered by a lack of knowledge on the spatial distribution and breeding habitats of this species. The ecological niche modeling framework used to predict the spatial distribution of this species, based on the maximum entropy and occurrence record data, allowed us to generate a species-specific spatial distribution map in Ladakh, Trans-Himalaya, India. The model was created by assimilating species occurrence data from 486 geographical sites with 24 topographic and bioclimatic variables. Fourteen variables helped forecast the distribution of black-necked cranes by 96.2%. The area under the curve score for the model training data was high (0.98), indicating the accuracy and predictive performance of the model. Of the total study area, the areas with high and moderate habitat suitability for black-necked cranes were anticipated to be 8,156 km² and 6,759 km², respectively. The area with high habitat suitability within the protected areas was 5,335 km². The spatial distribution predicted using our model showed that the majority of speculated conservation areas bordered the existing protected areas of the Changthang Wildlife Sanctuary. Hence, we believe, that by increasing the current study area, we can account for these gaps in conservation areas, more effectively.

• 한국통신학회논문지
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• 제40권12호
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• pp.2520-2527
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• 2015

작전을 수행하는 군 환경에서 위치 정보는 매우 중요하다. 군 환경에서 위치 정보 획득은 일반적으로 GPS에 의해 이루어진다. 하지만 GPS는 수신 신호의 세기가 매우 약해 전파교란에 취약하다는 단점이 있다. 이러한 단점을 해결하기 위해 많은 연구가 진행되고 있다. 상대항법은 전술데이터링크 표준인 JTIDS(Joint Tactical Information Distribution System)에서 정의된 GPS 보조항법이다. GPS 전파교란 환경에서 상대항법의 정확한 운용을 위해서는 지상에서 공중노드의 참조노드 역할을 수행하는 GRU(Ground Reference Unit)가 보장되어야한다. 하지만 상대항법을 운용하는데 있어서 GRU를 항상 보장하는 것은 쉬운 일이 아니다. GRU 부재 환경에서 상대항법 운용중인 공중노드는 관성항법장치에 의존하여 측위한다. 하지만 관성항법장치에 의존하는 측위는 시간이 지남에 따라 누적 오차 발생을 야기하며 누적 오차에 의해 공중노드는 정확한 측위를 할 수 없다. 본 논문에서는 상대항법에서 GRU 부재 시 관성항법장치 의존으로 인한 공중노드의 위치 오차를 줄이기 위한 대처 방안을 제시한다. 또한 대체 방안의 성능이 기존의 성능에 비하여 우수하다는 것을 모의실험을 통해 증명한다.

• Ocean and Polar Research
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• 제24권1호
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• pp.115-121
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• 2002

Yubu Island is located within the estuary of the Geum River, South Chungcheong Province $(35^{\circ}59'N,\;126^{\circ}36'E)$, Korea. The island is surrounded by a broad and sandy mudflat, which is typical in the west coast of Korea, and is located 4km off from Gunsan City. Less than 100 humans live on the island, occupying 30 houses. After we discovered that this island was a very important waterbird habitat especially for the East Asian subspecies of the Eurasian oystercatcher, Haematopus ostralegus osculans. Waterbirds were monitored once every month from August 1999 to July 2000. The highest number of oystercatchers counted was 3,200 in December 1999, and the birds seemed to remain in the area continuously from September to next February. About 200 breeding and non-breeding birds remained during the breeding season. In August, early migrants returned to the island, with the number reaching 1,060 individuals. This island is also very important for other waterbirds. Endangered or significant species occurring at this site, and their maximum counts were: chinese egret Egretta eulophotes (5), black-faced spoonbill Platalea minor (17), brant Branta bernicla (1), common shelduck Tadorna tadorna (8,000), hooded crane Grus monacha (2), spoon-billed sandpiper Ewynorhynchus pygmeus (7), dunlin Calidris alpina (6,500), great knot Calidris tenuirostris (24,000), far eastern curlew Numenius madagascariensis (2,500), spotted greenshank Tringa guttifer (4) and Saunders's gull Larus saundersi (1,200). During the 12 month survey period, we observed 52 waterbird species and the total of the maximum counts for the separate species was 73,308, implying that perhaps 150,000 birds could be using the immediate area, if a turnover rate of 2 was assumed.

• 한국환경생태학회지
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• 제16권4호
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• pp.487-497
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• 2003

문헌조사 결과 백두대간 남부지역 지리산-덕유산 구간에서는 지금까지 총 15목 45과 136종의 조류가 기록되었으며 지역별로는 지리산국립공원에서 132종, 함양 지역에서 63종, 장수지역에서 46종, 덕유산국립공원에서 69종이 기록되었다. 이들은 텃새 42종(30.9%). 여름철새 40종(29.4%), 겨울철새 31종(22.8%), 나그네새 23종(16.9%)으로 구성되었다. 법적 보호조류는 환경부 보호종 15종, 천연기념물은 14종으로 총 23종이 서식하는 것으로 조사되었다. 이들 중 붉은배새매, 새매, 황조롱이 등 3종만이 비교적 널리 분포하고 나머지 원앙 벌매, 참매, 조롱이, 털발말똥가리, 말똥가리, 잿빛개구리매, 쇠황조롱이 재두루미, 수리부엉이, 칡부엉이, 소쩍새, 큰소쩍새, 솔부엉이 올빼미, 가막딱다구리, 아물쇠딱다구리, 팔색조, 뿔종다리, 삼광조 등 20종은 모두 분포가 극히 제한되어 있는 것으로 나타나 이들에 대한 보호증식이 시급한 것으로 나타났다.