• Title/Summary/Keyword: association schemes

검색결과 425건 처리시간 0.028초

Assessment of Historical and Future Climatic Trends in Seti-Gandaki Basin of Nepal. A study based on CMIP6 Projections

  • Bastola Shiksha;Cho Jaepil;Jung Younghun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.162-162
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    • 2023
  • Climate change is a complex phenomenon having its impact on diverse sectors. Temperature and precipitation are two of the most fundamental variables used to characterize climate, and changes in these variables can have significant impacts on ecosystems, agriculture, and human societies. This study evaluated the historical (1981-2010) and future (2011-2100) climatic trends in the Seti-Gandaki basin of Nepal based on 5 km resolution Multi Model Ensemble (MME) of 18 Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) for SSP1-2.6, SSP2-4.5 and SSP5-85 scenarios. For this study, ERA5 reanalysis dataset is used for historical reference dataset instead of observation dataset due to a lack of good observation data in the study area. Results show that the basin has experienced continuous warming and an increased precipitation pattern in the historical period, and this rising trend is projected to be more prominent in the future. The Seti basin hosts 13 operational hydropower projects of different sizes, with 10 more planned by the government. Consequently, the findings of this study could be leveraged to design adaptation measures for existing hydropower schemes and provide a framework for policymakers to formulate climate change policies in the region. Furthermore, the methodology employed in this research could be replicated in other parts of the country to generate precise climate projections and offer guidance to policymakers in devising sustainable development plans for sectors like irrigation and hydropower.

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상수도 잔류염소농도 균등화를 위한 반응계수 추정 및 염소 재투입 최적화 (Reaction coefficient assessment and rechlorination optimization for chlorine residual equalization in water distribution networks)

  • 정기문;강두선;황태문
    • 한국수자원학회논문집
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    • 제55권spc1호
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    • pp.1197-1210
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    • 2022
  • 최근 국내에서는 관로 노후화 및 다양한 수질사고 발생으로 인해 상수도 분야에 대한 관심이 급증함에 따라, 상수도 서비스에 대한 이용자들의 수질민원 또한 증가하고 있다. 수질민원의 경우 실제 수질오염뿐만 아니라 소독을 위한 잔류염소농도에 대한 불편을 포함하고 있으며, 따라서 사용자에게 공급되는 잔류염소농도를 균등하게 유지하기 위해 재염소 처리와 같은 다양한 노력이 시도되고 있다. 본 연구에서는 상수관망 내 잔류염소농도 모의를 위해 적용 대상지역의 수질반응계수를 추정하였으며, 수질기준을 만족시키는 동시에 잔류염소농도 균등화를 고려하기 위한 염소 투입 및 재투입 최적화 방법을 제안하였다. 제안된 방법은 국내 대규모 지방상수도를 대상으로 적용하였으며, 격자탐색법을 통해 다양한 염소 투입/재투입 계획을 비교 분석하고, 공급 잔류염소농도의 적합성 및 균등성을 중심으로 최적화한 결과를 제시하였다.

Analysis of streamflow prediction performance by various deep learning schemes

  • Le, Xuan-Hien;Lee, Giha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2021년도 학술발표회
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    • pp.131-131
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    • 2021
  • Deep learning models, especially those based on long short-term memory (LSTM), have presented their superiority in addressing time series data issues recently. This study aims to comprehensively evaluate the performance of deep learning models that belong to the supervised learning category in streamflow prediction. Therefore, six deep learning models-standard LSTM, standard gated recurrent unit (GRU), stacked LSTM, bidirectional LSTM (BiLSTM), feed-forward neural network (FFNN), and convolutional neural network (CNN) models-were of interest in this study. The Red River system, one of the largest river basins in Vietnam, was adopted as a case study. In addition, deep learning models were designed to forecast flowrate for one- and two-day ahead at Son Tay hydrological station on the Red River using a series of observed flowrate data at seven hydrological stations on three major river branches of the Red River system-Thao River, Da River, and Lo River-as the input data for training, validation, and testing. The comparison results have indicated that the four LSTM-based models exhibit significantly better performance and maintain stability than the FFNN and CNN models. Moreover, LSTM-based models may reach impressive predictions even in the presence of upstream reservoirs and dams. In the case of the stacked LSTM and BiLSTM models, the complexity of these models is not accompanied by performance improvement because their respective performance is not higher than the two standard models (LSTM and GRU). As a result, we realized that in the context of hydrological forecasting problems, simple architectural models such as LSTM and GRU (with one hidden layer) are sufficient to produce highly reliable forecasts while minimizing computation time because of the sequential data nature.

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Strategies to improve irrigation water management for rice production in Pulangui River Irrigation System

  • Siem, Paul Roderick M.;Ahmad, Mirza Junaid;Choi, Kyung-Sook
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.509-509
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    • 2022
  • Rice has always been the anchor of food security in the Philippines and the government is adamant about sustaining rice production by ensuring reliable irrigation water availability. Among the numerous irrigation schemes, the importance of the Pulangui River Irrigation System (PRIS) is undeniable, as it is the largest and primary irrigation source for rice production areas which are considered the food basket in Northern Mindanao. However, the ageing irrigation structures, unlined canals, long-standing water delivery systems, and climate change are compromising the performance of PRIS; and every year, during the dry and wet season, the maximum rice irrigable area is not achieved. From the field-scale water management perspective, untimely irrigation application, an unregulated roster of turn for irrigation among farmers, and the traditional practice of flooding the rice fields are the main causes of substantial water losses in conveyance, distribution, and farm application of irrigation water. Hence, proper irrigation scheduling is crucial to cultivate the maximum irrigable area by ensuring equity among the farmers and to increase the water use efficiency and yield. In this study, the FAO single crop coefficient approach was adopted to estimate rice water requirements, which were subsequently used to suggest appropriate irrigation schedules based on the recommended field-scale rice cultivation practices. The study results would improve the irrigation system management in the study area by facilitating in regulating the canal water flows and releases according to suggested irrigation schedules that could lead to increased benefited area, yield, and water efficiency without straining the available water resources.

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A Review of the Application of Constructed Wetlands as Stormwater Treatment Systems

  • Reyes, Nash Jett;Geronimo, Franz Kevin;Guerra, Heidi;Jeon, Minsu;Kim, Lee-Hyung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.162-162
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    • 2022
  • Stormwater management is an essential component of land-use planning and development. Due to the additional challenges posed by climate change and urbanization, various stormwater management schemes have been developed to limit flood damages and ease water quality concerns. Nature-based solutions (NBS) are increasingly used as cost-effective measures to manage stormwater runoff from various land uses. Specifically, constructed wetlands were already considered as socially acceptable green stormwater infrastructures that are widely used in different countries. There is a large collection of published literature regarding the effectiveness or efficiency of constructed wetlands in treating stormwater runoff; however, metadata analyses using bibliographic information are very limited or seldomly explored. This study was conducted to determine the trends of publication regarding stormwater treatment wetlands using a bibliometric analysis approach. Moreover, the research productivity of various countries, authors, and institutions were also identified in the study. The Web of Science (WoS) database was utilized to retrieve bibliographic information. The keywords ("constructed wetland*" OR "treatment wetland*" OR "engineered wetland*" OR "artificial wetland*") AND ("stormwater*" or "storm water*") were used to retrieve pertinent information on stormwater treatment wetlands-related publication from 1990 up to 2021. The network map of keyword co-occurrence map was generated through the VOSviewer software and the contingency matrices were obtained using the Cortext platform (www.cortext.net). The results obtained from this inquiry revealed the areas of research that have been adequately explored by past studies. Furthermore, the extensive collection of published scientific literature enabled the identification of existing knowledge gaps in the field of stormwater treatment wetlands.

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워드 임베딩 기반 근사 Top-k 레이블 서브그래프 매칭 기법 (Approximate Top-k Labeled Subgraph Matching Scheme Based on Word Embedding)

  • 최도진;오영호;복경수;유재수
    • 한국콘텐츠학회논문지
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    • 제22권8호
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    • pp.33-43
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    • 2022
  • 지식 그래프 및 단백질 상호 작용과 같은 실제 데이터에서 개체들과 개체들의 관계 및 구조를 나타내기 위해 레이블 그래프를 사용한다. IT의 급속한 발전과 데이터의 폭발적인 증가로 사용자에게 관심 있는 정보를 제공하기 위한 서브 그래프 매칭 기술이 필요하다. 본 논문은 레이블의 의미적 유사성과 그래프 구조 차이를 고려한 근사 Top-k 서브 그래프 매칭 기법을 제안한다. 제안하는 기법은 레이블 의미적 유사도를 고려하기 위하여 FastText을 활용한 학습 모델을 이용한다. 레이블 간 의미적 유사도를 미리 계산한 LSG(Label Similarity Graph)를 통해 처리 속도의 효율을 높인다. LSG를 통해 레이블이 정확하게 일치해야 확장이 가능한 기존 연구의 한계를 해결한다. 2-hop까지 탐색을 수행함으로써 질의 그래프에 대한 구조적 유사성을 지원한다. 매칭된 서브 그래프는 유사도 값 기반으로 Top-k 결과를 제공한다. 제안하는 기법의 우수성을 보이기 위하여 다양한 성능평가를 수행한다.

한라산국립공원 어리목-영실탐방로의 해설표지판 분석 (An Analysis of Self-guided Interpretive Signs along Eorimok-Yeongsil Trail on Mt. Hallasan National Park)

  • 고지희;김태호
    • 한국지형학회지
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    • 제26권4호
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    • pp.123-140
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    • 2019
  • This study analyzed problems of interpretive signs along Eorimok-Yeongsil Trail on Mt. Hallasan National Park, focusing on factors of distracting visitor's attention from reading and understanding the signs. Eorimok-Yeongsil Trail has a total of 86 signs, and according to their purpose and content, they are classified into thirteen general signs, sixteen location signs, nine safety signs and forty-eight interpretive signs. Interpretive signs provide visitors with information and explanations about the nature and human resources of Mt. Hallasan as well as enhancing the opportunity for self-guided interpretation. The contents of interpretive signs of Eorimok-Yeongsil Trail are composed of landscapes, flora and fauna, topography, geology, history and culture, of which 70.8% of the total are related to plants and animals. Interpretive signs on the Eorimok-Yeongsil Trail do not attract visitors' attention because of the low readability, inappropriate locations and frequent errors in translation from Korean into other languages. The causes of low readability of interpretive signs include thirty-six physically damaged and faded signs, twenty-two improper font sizes and misuse of color schemes and five unclear description signs. The reasons for the incorrect locations include twenty-two long distances from the trails, twenty-one inadequate heights and fifteen inconsistencies in descriptions and locations. Problems with English use include eight grammar and spelling errors, twenty-one incorrect translations, and twenty-six English names missing.

Association of UDP-galactose-4-epimerase with milk protein concentration in the Chinese Holstein population

  • Li, Cong;Cai, Wentao;Liu, Shuli;Zhou, Chenghao;Cao, Mingyue;Yin, Hongwei;Sun, Dongxiao;Zhang, Shengli;Loor, Juan J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권11호
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    • pp.1725-1731
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    • 2020
  • Objective: An initial RNA-Sequencing study revealed that UDP-galactose-4-epimerase (GALE) was one of the most promising candidates for milk protein concentration in Chinese Holstein cattle. This enzyme catalyzes the interconversion of UDP-galactose and UDP-glucose, an important step in galactose catabolism. To further validate the genetic effect of GALE on milk protein traits, genetic variations were identified, and genotypes-phenotypes associations were performed. Methods: The entire coding region and the 5'-regulatory region (5'-UTR) of GALE were re-sequenced using pooled DNA of 17 unrelated sires. Association studies for five milk production traits were performed using a mixed linear animal model with a population encompassing 1,027 Chinese Holstein cows. Results: A total of three variants in GALE were identified, including two novel variants (g.2114 A>G and g.2037 G>A) in the 5'-UTR and one previously reported variant (g.3836 G>C) in an intron. All three single nucleotide polymorphisms (SNPs) were associated with milk yield (p<0.0001), fat yield (p = 0.0006 to <0.0001), protein yield (p = 0.0232 to <0.0001) and protein percentage (p<0.0001), while no significant associations were detected between the SNPs and fat percentage. A strong linkage disequilibrium (D' = 0.96 to 1.00) was observed among all three SNPs, and a 5 Kb haplotype block involving three main haplotypes with GAG, AGC, and AGG was formed. The results of haplotype association analyses were consistent with the results of single locus association analysis (p<0.0001). The phenotypic variance ratio above 3.00% was observed for milk protein yield that was explained by SNP-g.3836G >C. Conclusion: Overall, our findings provided new insights into the polymorphic variations in bovine GALE gene and their associations with milk protein concentration. The data indicate their potential uses for marker-assisted breeding or genetic selection schemes.

Optimization of Swine Breeding Programs Using Genomic Selection with ZPLAN+

  • Lopez, B.M.;Kang, H.S.;Kim, T.H.;Viterbo, V.S.;Kim, H.S.;Na, C.S.;Seo, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권5호
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    • pp.640-645
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    • 2016
  • The objective of this study was to evaluate the present conventional selection program of a swine nucleus farm and compare it with a new selection strategy employing genomic enhanced breeding value (GEBV) as the selection criteria. The ZPLAN+ software was employed to calculate and compare the genetic gain, total cost, return and profit of each selection strategy. The first strategy reflected the current conventional breeding program, which was a progeny test system (CS). The second strategy was a selection scheme based strictly on genomic information (GS1). The third scenario was the same as GS1, but the selection by GEBV was further supplemented by the performance test (GS2). The last scenario was a mixture of genomic information and progeny tests (GS3). The results showed that the accuracy of the selection index of young boars of GS1 was 26% higher than that of CS. On the other hand, both GS2 and GS3 gave 31% higher accuracy than CS for young boars. The annual monetary genetic gain of GS1, GS2 and GS3 was 10%, 12%, and 11% higher, respectively, than that of CS. As expected, the discounted costs of genomic selection strategies were higher than those of CS. The costs of GS1, GS2 and GS3 were 35%, 73%, and 89% higher than those of CS, respectively, assuming a genotyping cost of $120. As a result, the discounted profit per animal of GS1 and GS2 was 8% and 2% higher, respectively, than that of CS while GS3 was 6% lower. Comparison among genomic breeding scenarios revealed that GS1 was more profitable than GS2 and GS3. The genomic selection schemes, especially GS1 and GS2, were clearly superior to the conventional scheme in terms of monetary genetic gain and profit.

전자무역 해외마케팅 교육과 연구체계 수립에 관한 연구 (A study on the research scheme and the education of e-trade marketing in Korea)

  • 강효원
    • 통상정보연구
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    • 제15권3호
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    • pp.411-430
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    • 2013
  • 전자무역의 단계별 성과를 볼 때 계약체결 이전 단계의 해외마케팅은 해외시장진출의 가장 큰 장애요인이면서 가장 많은 역량이 투여되는 부문으로 이에 대한 교육 및 연구체계를 재정립할 필요가 있다. 전자무역은 인터넷과 정보통신기술의 발전에 따른 파생적 수요성격이 강한 학문적 영역으로 무역실무와 더불어 무역학의 핵심주제로 부각되고 있다. 그러나 2000년대 중반이후 전자무역 관련분야 연구와 교육교재개발 등이 점차 감소되고 있는 실정이다. 따라서 본 연구에서는 우리나라 전자무역 중 해외마케팅의 측면에서 교육 및 학문적 연구체계와 성과를 검토하고 향후 해외마케팅 부문 교육과 연구체계 수립에 대한 방향을 제시하였다. 그 결과 전자무역관련 교육 및 연구 중 산업계에서 활성화되고 있는 검색엔진마케팅, 검색엔진최적화, 소셜네트워크분석 등에 대한 교육 및 연구체계를 확립해 나가는 것이 시급하다고 할 수 있다. 또한 이론과 실무가 접목되어 병행되는 캡스톤디자인 교과목의 도입이 필요하다고 할 수 있다.

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