5,611 research outputs found

    Application of Fuzzy Cognitive Mapping in Livelihood Vulnerability Analysis

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    Feedback mechanisms are important in the analysis of vulnerability and resilience of social-ecological systems, as well as in the analysis of livelihoods, but how to evaluate systems with direct feedbacks has been a great challenge. We applied fuzzy cognitive mapping, a tool that allows analysis of both direct and indirect feedbacks and can be used to explore the vulnerabilities of livelihoods to identified hazards. We studied characteristics and drivers of rural livelihoods in the Great Limpopo Transfrontier Conservation Area in southern Africa to assess the vulnerability of inhabitants to the different hazards they face. The process involved four steps: (1) surveys and interviews to identify the major livelihood types; (2) description of specific livelihood types in a system format using fuzzy cognitive maps (FCMs), a semi-quantitative tool that models systems based on people’s knowledge; (3) linking variables and drivers in FCMs by attaching weights; and (4) defining and applying scenarios to visualize the effects of drought and changing park boundaries on cash and household food security. FCMs successfully gave information concerning the nature (increase or decrease) and magnitude by which a livelihood system changed under different scenarios. However, they did not explain the recovery path in relation to time and pattern (e.g., how long it takes for cattle to return to desired numbers after a drought). Using FCMs revealed that issues of policy, such as changing situations at borders, can strongly aggravate effects of climate change such as drought. FCMs revealed hidden knowledge and gave insights that improved the understanding of the complexity of livelihood systems in a way that is better appreciated by stakeholders

    Expert System for Crop Disease based on Graph Pattern Matching: A proposal

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    Para la agroindustria, las enfermedades en cultivos constituyen uno de los problemas más frecuentes que generan grandes pérdidas económicas y baja calidad en la producción. Por otro lado, desde las ciencias de la computación, han surgido diferentes herramientas cuya finalidad es mejorar la prevención y el tratamiento de estas enfermedades. En este sentido, investigaciones recientes proponen el desarrollo de sistemas expertos para resolver este problema haciendo uso de técnicas de minería de datos e inteligencia artificial, como inferencia basada en reglas, árboles de decisión, redes bayesianas, entre otras. Además, los grafos pueden ser usados para el almacenamiento de los diferentes tipos de variables que se encuentran presentes en un ambiente de cultivos, permitiendo la aplicación de técnicas de minería de datos en grafos, como el emparejamiento de patrones en los mismos. En este artículo presentamos una visión general de las temáticas mencionadas y una propuesta de un sistema experto para enfermedades en cultivos, basado en emparejamiento de patrones en grafos.For agroindustry, crop diseases constitute one of the most common problems that generate large economic losses and low production quality. On the other hand, from computer science, several tools have emerged in order to improve the prevention and treatment of these diseases. In this sense, recent research proposes the development of expert systems to solve this problem, making use of data mining and artificial intelligence techniques like rule-based inference, decision trees, Bayesian network, among others. Furthermore, graphs can be used for storage of different types of variables that are present in an environment of crops, allowing the application of graph data mining techniques like graph pattern matching. Therefore, in this paper we present an overview of the above issues and a proposal of an expert system for crop disease based on graph pattern matching

    Multiple Quantitative Trait Analysis Using Bayesian Networks

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    Models for genome-wide prediction and association studies usually target a single phenotypic trait. However, in animal and plant genetics it is common to record information on multiple phenotypes for each individual that will be genotyped. Modeling traits individually disregards the fact that they are most likely associated due to pleiotropy and shared biological basis, thus providing only a partial, confounded view of genetic effects and phenotypic interactions. In this paper we use data from a Multiparent Advanced Generation Inter-Cross (MAGIC) winter wheat population to explore Bayesian networks as a convenient and interpretable framework for the simultaneous modeling of multiple quantitative traits. We show that they are equivalent to multivariate genetic best linear unbiased prediction (GBLUP), and that they are competitive with single-trait elastic net and single-trait GBLUP in predictive performance. Finally, we discuss their relationship with other additive-effects models and their advantages in inference and interpretation. MAGIC populations provide an ideal setting for this kind of investigation because the very low population structure and large sample size result in predictive models with good power and limited confounding due to relatedness.Comment: 28 pages, 1 figure, code at http://www.bnlearn.com/research/genetics1

    Novel Bayesian Networks for Genomic Prediction of Developmental Traits in Biomass Sorghum.

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    The ability to connect genetic information between traits over time allow Bayesian networks to offer a powerful probabilistic framework to construct genomic prediction models. In this study, we phenotyped a diversity panel of 869 biomass sorghum (Sorghum bicolor (L.) Moench) lines, which had been genotyped with 100,435 SNP markers, for plant height (PH) with biweekly measurements from 30 to 120 days after planting (DAP) and for end-of-season dry biomass yield (DBY) in four environments. We evaluated five genomic prediction models: Bayesian network (BN), Pleiotropic Bayesian network (PBN), Dynamic Bayesian network (DBN), multi-trait GBLUP (MTr-GBLUP), and multi-time GBLUP (MTi-GBLUP) models. In fivefold cross-validation, prediction accuracies ranged from 0.46 (PBN) to 0.49 (MTr-GBLUP) for DBY and from 0.47 (DBN, DAP120) to 0.75 (MTi-GBLUP, DAP60) for PH. Forward-chaining cross-validation further improved prediction accuracies of the DBN, MTi-GBLUP and MTr-GBLUP models for PH (training slice: 30-45 DAP) by 36.4-52.4% relative to the BN and PBN models. Coincidence indices (target: biomass, secondary: PH) and a coincidence index based on lines (PH time series) showed that the ranking of lines by PH changed minimally after 45 DAP. These results suggest a two-level indirect selection method for PH at harvest (first-level target trait) and DBY (second-level target trait) could be conducted earlier in the season based on ranking of lines by PH at 45 DAP (secondary trait). With the advance of high-throughput phenotyping technologies, our proposed two-level indirect selection framework could be valuable for enhancing genetic gain per unit of time when selecting on developmental traits

    Metamodeling of Bayesian networks for decision-support systems development

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    The knowledge modeling and software modeling phases in Knowledge-Based System development are not integrable, in terms of representation, due to the different languages needed at the steps of the development. This paper focuses on bring closer these languages. By one hand, we define a meta model which contains the key concepts used in the definition of a knowledge model as a Bayesian network. On the other hand, we define an extension of UML using profiles that can bridge the gap in representation and facilitate the seamless incorporation of a knowledge model, as Bayesian network, in the context of a knowledge-based software development

    Review—Machine Learning Techniques in Wireless Sensor Network Based Precision Agriculture

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    The use of sensors and the Internet of Things (IoT) is key to moving the world\u27s agriculture to a more productive and sustainable path. Recent advancements in IoT, Wireless Sensor Networks (WSN), and Information and Communication Technology (ICT) have the potential to address some of the environmental, economic, and technical challenges as well as opportunities in this sector. As the number of interconnected devices continues to grow, this generates more big data with multiple modalities and spatial and temporal variations. Intelligent processing and analysis of this big data are necessary to developing a higher level of knowledge base and insights that results in better decision making, forecasting, and reliable management of sensors. This paper is a comprehensive review of the application of different machine learning algorithms in sensor data analytics within the agricultural ecosystem. It further discusses a case study on an IoT based data-driven smart farm prototype as an integrated food, energy, and water (FEW) system

    딥러닝 방법론을 이용한 높은 적용성을 가진 수경재배 파프리카 대상 절차 기반 모델 개발

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    학위논문(박사) -- 서울대학교대학원 : 농업생명과학대학 농림생물자원학부, 2022. 8. 손정익.Many agricultural challenges are entangled in a complex interaction between crops and the environment. As a simplifying tool, crop modeling is a process of abstracting and interpreting agricultural phenomena. Understanding based on this interpretation can play a role in supporting academic and social decisions in agriculture. Process-based crop models have solved the challenges for decades to enhance the productivity and quality of crop production; the remaining objectives have led to demand for crop models handling multidirectional analyses with multidimensional information. As a possible milestone to satisfy this goal, deep learning algorithms have been introduced to the complicated tasks in agriculture. However, the algorithms could not replace existing crop models because of the research fragmentation and low accessibility of the crop models. This study established a developmental protocol for a process-based crop model with deep learning methodology. Literature Review introduced deep learning and crop modeling, and it explained the reasons for the necessity of this protocol despite numerous deep learning applications for agriculture. Base studies were conducted with several greenhouse data in Chapters 1 and 2: transfer learning and U-Net structure were utilized to construct an infrastructure for the deep learning application; HyperOpt, a Bayesian optimization method, was tested to calibrate crop models to compare the existing crop models with the developed model. Finally, the process-based crop model with full deep neural networks, DeepCrop, was developed with an attention mechanism and multitask decoders for hydroponic sweet peppers (Capsicum annuum var. annuum) in Chapter 3. The methodology for data integrity showed adequate accuracy, so it was applied to the data in all chapters. HyperOpt was able to calibrate food and feed crop models for sweet peppers. Therefore, the compared models in the final chapter were optimized using HyperOpt. DeepCrop was trained to simulate several growth factors with environment data. The trained DeepCrop was evaluated with unseen data, and it showed the highest modeling efficiency (=0.76) and the lowest normalized root mean squared error (=0.18) than the compared models. With the high adaptability of DeepCrop, it can be used for studies on various scales and purposes. Since all methods adequately solved the given tasks and underlay the DeepCrop development, the established protocol can be a high throughput for enhancing accessibility of crop models, resulting in unifying crop modeling studies.농업 시스템에서 발생하는 문제들은 작물과 환경의 상호작용 하에 복잡하게 얽혀 있다. 작물 모델링은 대상을 단순화하는 방법으로써, 농업에서 일어나는 현상을 추상화하고 해석하는 과정이다. 모델링을 통해 대상을 이해하는 것은 농업 분야의 학술적 및 사회적 결정을 지원할 수 있다. 지난 수년 간 절차 기반 작물 모델은 농업의 문제들을 해결하여 작물 생산성 및 품질을 증진시켰으며, 현재 작물 모델링에 남아있는 과제들은 다차원 정보를 다방향에서 분석할 수 있는 작물 모델을 필요로 하게 되었다. 이를 만족시킬 수 있는 지침으로써, 복잡한 농업적 과제들을 목표로 딥러닝 알고리즘이 도입되었다. 그러나, 이 알고리즘들은 낮은 데이터 완결성 및 높은 연구 다양성 때문에 기존의 작물 모델들을 대체하지는 못했다. 본 연구에서는 딥러닝 방법론을 이용하여 절차 기반 작물 모델을 구축하는 개발 프로토콜을 확립하였다. Literature Review에서는 딥러닝과 작물 모델에 대해 소개하고, 농업으로의 딥러닝 적용 연구가 많음에도 이 프로토콜이 필요한 이유를 설명하였다. 제1장과 2장에서는 국내 여러 지역의 데이터를 이용하여 전이 학습 및 U-Net 구조를 활용하여 딥러닝 모델 적용을 위한 기반을 마련하고, 베이지안 최적화 방법인 HyperOpt를 사용하여 기존 모델과 딥러닝 기반 모델을 비교하기 위해 시험적으로 WOFOST 작물 모델을 보정하는 등 모델 개발을 위한 기반 연구를 수행하였다. 마지막으로, 제3장에서는 주의 메커니즘 및 다중 작업 디코더를 가진 완전 심층 신경망 절차 기반 작물 모델인 DeepCrop을 수경재배 파프리카(Capsicum annuum var. annuum) 대상으로 개발하였다. 데이터 완결성을 위한 기술들은 적합한 정확도를 보여주었으며, 전체 챕터 데이터에 적용하였다. HyperOpt는 식량 및 사료 작물 모델들을 파프리카 대상으로 보정할 수 있었다. 따라서, 제3장의 비교 대상 모델들에 대해 HyperOpt를 사용하였다. DeepCrop은 환경 데이터를 이용하고 여러 생육 지표를 예측하도록 학습되었다. 학습에 사용하지 않은 데이터를 이용하여 학습된 DeepCrop를 평가하였으며, 이 때 비교 모델들 중 가장 높은 모형 효율(EF=0.76)과 가장 낮은 표준화 평균 제곱근 오차(NRMSE=0.18)를 보여주었다. DeepCrop은 높은 적용성을 기반으로 다양한 범위와 목적을 가진 연구에 사용될 수 있을 것이다. 모든 방법들이 주어진 작업을 적절히 풀어냈고 DeepCrop 개발의 근거가 되었으므로, 본 논문에서 확립한 프로토콜은 작물 모델의 접근성을 향상시킬 수 있는 획기적인 방향을 제시하였고, 작물 모델 연구의 통합에 기여할 수 있을 것으로 기대한다.LITERATURE REVIEW 1 ABSTRACT 1 BACKGROUND 3 REMARKABLE APPLICABILITY AND ACCESSIBILITY OF DEEP LEARNING 12 DEEP LEARNING APPLICATIONS FOR CROP PRODUCTION 17 THRESHOLDS TO APPLY DEEP LEARNING TO CROP MODELS 18 NECESSITY TO PRIORITIZE DEEP-LEARNING-BASED CROP MODELS 20 REQUIREMENTS OF THE DEEP-LEARNING-BASED CROP MODELS 21 OPENING REMARKS AND THESIS OBJECTIVES 22 LITERATURE CITED 23 Chapter 1 34 Chapter 1-1 35 ABSTRACT 35 INTRODUCTION 37 MATERIALS AND METHODS 40 RESULTS 50 DISCUSSION 59 CONCLUSION 63 LITERATURE CITED 64 Chapter 1-2 71 ABSTRACT 71 INTRODUCTION 73 MATERIALS AND METHODS 75 RESULTS 84 DISCUSSION 92 CONCLUSION 101 LITERATURE CITED 102 Chapter 2 108 ABSTRACT 108 NOMENCLATURE 110 INTRODUCTION 112 MATERIALS AND METHODS 115 RESULTS 124 DISCUSSION 133 CONCLUSION 137 LITERATURE CITED 138 Chapter 3 144 ABSTRACT 144 INTRODUCTION 146 MATERIALS AND METHODS 149 RESULTS 169 DISCUSSION 182 CONCLUSION 187 LITERATURE CITED 188 GENERAL DISCUSSION 196 GENERAL CONCLUSION 201 ABSTRACT IN KOREAN 203 APPENDIX 204박

    Artificial neural networks compared with Bayesian generalized linear regression for leaf rust resistance prediction in Arabica coffee.

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    The objective of this work was to evaluate the use of artificial neural networks in comparison with Bayesian generalized linear regression to predict leaf rust resistance in Arabica coffee (Coffea arabica). This study used 245 individuals of a F2 population derived from the self-fertilization of the F1 H511-1 hybrid, resulting from a crossing between the susceptible cultivar Catuaí Amarelo IAC 64 (UFV 2148-57) and the resistant parent Híbrido de Timor (UFV 443-03). The 245 individuals were genotyped with 137 markers. Artificial neural networks and Bayesian generalized linear regression analyses were performed. The artificial neural networks were able to identify four important markers belonging to linkage groups that have been recently mapped, while the Bayesian generalized model identified only two markers belonging to these groups. Lower prediction error rates (1.60%) were observed for predicting leaf rust resistance in Arabica coffee when artificial neural networks were used instead of Bayesian generalized linear regression (2.4%). The results showed that artificial neural networks are a promising approach for predicting leaf rust resistance in Arabica coffee.Título em português: Redes neurais artificiais comparadas com modelos lineares generalizados sob o enfoque bayesiano para predição de resistência à ferrugem em café arábica

    What makes or breaks a campaign to stop an invading plant pathogen?

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    Diseases in humans, animals and plants remain an important challenge in our society. Effective control of invasive pathogens often requires coordinated concerted action of a large group of stakeholders. Both epidemiological and human behavioural factors influence the outcome of a disease control campaign. In mathematical models that are frequently used to guide such campaigns, human behaviour is often ill-represented, if at all. Existing models of human, animal and plant disease that do incorporate participation or compliance are often driven by pay-offs or direct observations of the disease state. It is however very well known that opinion is an important driving factor of human decision making. Here we consider the case study of Citrus Huanglongbing disease (HLB), which is an acute bacterial disease that threatens the sustainability of citrus production across the world. We show how by coupling an epidemiological model of this invasive disease with an opinion dynamics model we are able to answer the question: What makes or breaks the effectiveness of a disease control campaign? Frequent contact between stakeholders and advisors is shown to increase the probability of successful control. More surprisingly, we show that informing stakeholders about the effectiveness of control methods is of much greater importance than prematurely increasing their perceptions of the risk of infection. We discuss the overarching consequences of this finding and the effect on human as well as plant disease epidemics
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