Reconocimiento de animales desde imágenes utilizando aprendizaje por transferencia

Automatic image-based recognition systems have been widely used to solve different computer vision tasks. In particular, animals' identification in farms is a research field of interest for the computer vision and the agriculture community. It is then necessary to develop robust and precise algorithms to support detection, recognition, and monitoring tasks to enhance farm management. Traditionally, deep learning approaches have been proposed to solve image-based detection tasks. Nonetheless, databases holding many instances are required to achieve competitive performances, not mentioning the hyperparameters tuning issues. In this paper, we propose a transfer learning approach for image-based animal recognition. We enhance a pre-trained Convolutional Neural Network model for animal classification from noisy and low-quality images. First, a dog vs. cat task is tested from the well-known CIFAR database. Further, a cow vs. no cow database is built to test our transfer learning approach. The achieved results show competitive classification performance using different types of architectures compared to state-of-the-art methodologies.Los sistemas de reconocimiento automático basados en imágenes se han utilizado ampliamente para resolver diferentes tareas de visión por computador. En particular, la identificación de animales en granjas es un campo de investigación de interés para comunidad relacionada con visión artificial y agricultura. En este sentido, es necesario desarrollar algoritmos robustos y precisos para respaldar las tareas de detección, reconocimiento y monitoreo, en aras de apoyar la gestión de granjas en agricultura. Tradicionalmente, se han propuesto enfoques de aprendizaje profundo para resolver tareas de detección basadas en imágenes. No obstante, se requieren de bases de datos con muchas instancias para lograr un rendimiento competitivo, sin mencionar los problemas de ajuste de los hiperparámetros. En este artículo, proponemos un enfoque de aprendizaje por transferencia para el reconocimiento de animales basado en imágenes. En particular, mejoramos un modelo de red neuronal convolucional previamente entrenado para la clasificación de animales a partir de imágenes ruidosas y de baja calidad. Primero, se prueba una tarea de perro contra gato a partir de la conocida base de datos CIFAR. Además, se crea una base de datos de vaca versus no vaca para probar nuestro enfoque de aprendizaje por transferencia. Los resultados obtenidos muestran un rendimiento de clasificación competitivo utilizando diferentes tipos de arquitecturas, en comparación con las metodologías actuales

Reconocimiento de animales desde imágenes utilizando aprendizaje por transferencia

Automatic image-based recognition systems have been widely used to solve different computer vision tasks. In particular, animals' identification in farms is a research field of interest for the computer vision and the agriculture community. It is then necessary to develop robust and precise algorithms to support detection, recognition, and monitoring tasks to enhance farm management. Traditionally, deep learning approaches have been proposed to solve image-based detection tasks. Nonetheless, databases holding many instances are required to achieve competitive performances, not mentioning the hyperparameters tuning issues. In this paper, we propose a transfer learning approach for image-based animal recognition. We enhance a pre-trained Convolutional Neural Network model for animal classification from noisy and low-quality images. First, a dog vs. cat task is tested from the well-known CIFAR database. Further, a cow vs. no cow database is built to test our transfer learning approach. The achieved results show competitive classification performance using different types of architectures compared to state-of-the-art methodologies.Los sistemas de reconocimiento automático basados en imágenes se han utilizado ampliamente para resolver diferentes tareas de visión por computador. En particular, la identificación de animales en granjas es un campo de investigación de interés para comunidad relacionada con visión artificial y agricultura. En este sentido, es necesario desarrollar algoritmos robustos y precisos para respaldar las tareas de detección, reconocimiento y monitoreo, en aras de apoyar la gestión de granjas en agricultura. Tradicionalmente, se han propuesto enfoques de aprendizaje profundo para resolver tareas de detección basadas en imágenes. No obstante, se requieren de bases de datos con muchas instancias para lograr un rendimiento competitivo, sin mencionar los problemas de ajuste de los hiperparámetros. En este artículo, proponemos un enfoque de aprendizaje por transferencia para el reconocimiento de animales basado en imágenes. En particular, mejoramos un modelo de red neuronal convolucional previamente entrenado para la clasificación de animales a partir de imágenes ruidosas y de baja calidad. Primero, se prueba una tarea de perro contra gato a partir de la conocida base de datos CIFAR. Además, se crea una base de datos de vaca versus no vaca para probar nuestro enfoque de aprendizaje por transferencia. Los resultados obtenidos muestran un rendimiento de clasificación competitivo utilizando diferentes tipos de arquitecturas, en comparación con las metodologías actuales

A review on detecting brain tumors using deep learning and magnetic resonance images

Early detection and treatment in the medical field offer a critical opportunity to survive people. However, the brain has a significant role in human life as it handles most human body activities. Accurate diagnosis of brain tumors dramatically helps speed up the patient's recovery and the cost of treatment. Magnetic resonance imaging (MRI) is a commonly used technique due to the massive progress of artificial intelligence in medicine, machine learning, and recently, deep learning has shown significant results in detecting brain tumors. This review paper is a comprehensive article suitable as a starting point for researchers to demonstrate essential aspects of using deep learning in diagnosing brain tumors. More specifically, it has been restricted to only detecting brain tumors (binary classification as normal or tumor) using MRI datasets in 2020 and 2021. In addition, the paper presents the frequently used datasets, convolutional neural network architectures (standard and designed), and transfer learning techniques. The crucial limitations of applying the deep learning approach, including a lack of datasets, overfitting, and vanishing gradient problems, are also discussed. Finally, alternative solutions for these limitations are obtained

Modelo para la clasificación del aguacate Hass en sus estados comerciales y de exportación, mediante el uso de redes neuronales convolucionales

El mercado del aguacate hass en Colombia ha tenido un crecimiento en los últimos años debido a su alta comercialización internacional, por este motivo se han gestado procesos de producción del aguacate hass en todo el territorio nacional con una pronunciada influencia de inversionistas extranjeros. En el caso particular del departamento de Risaralda se ha generado mucho interés por introducirse en el mercado del aguacate Hass en especial en pequeños y medianos productores de la agroindustria, ellos están optando por la producción masiva de este fruto, sin embargo, luego de un estudio de campo, se pudo determinar que para poder ser exportado, el aguacate debe cumplir con ciertas condiciones fisiológicas y físicas, este proceso de clasificación se realiza de manera manual en la mayoría de los casos..

Modelo para la clasificación del aguacate Hass en sus estados comerciales y de exportación, mediante el uso de redes neuronales convolucionales

El mercado del aguacate hass en Colombia ha tenido un crecimiento en los últimos años debido a su alta comercialización internacional, por este motivo se han gestado procesos de producción del aguacate hass en todo el territorio nacional con una pronunciada influencia de inversionistas extranjeros. En el caso particular del departamento de Risaralda se ha generado mucho interés por introducirse en el mercado del aguacate Hass en especial en pequeños y medianos productores de la agroindustria, ellos están optando por la producción masiva de este fruto, sin embargo, luego de un estudio de campo, se pudo determinar que para poder ser exportado, el aguacate debe cumplir con ciertas condiciones fisiológicas y físicas, este proceso de clasificación se realiza de manera manual en la mayoría de los casos..

Klasifikasi Citra Mutu Cengkeh (Syzygium Aromaticum) Di PT. Perkebunan Nusantara 12 Kabupaten Malang Menggunakan Deep Convolutional Neural Network (DCNN).

Pada tanaman cengkeh, salah satu bagian tanaman yang dimanfaatkan yaitu bunga cengkeh. Proses pemanenan bunga cengkeh dengan cara memetik bunga cengkih yang masih kuncup. Bunga cengkeh akan dikeringkan sampai berwarna kecloklatan sesuai dengan standart mutunya. Standart mutu cengkeh kering yaitu SNI 01-3392-1994 dan ISO 2254-2004. Kualitas dari bunga cengkeh kering mempengaruhi harga jual untuk ekspor dan untuk dalam negeri. Kondisi saat ini pada petani dan di PTPN 12, proses klasifikasi mutu cengkeh dilakukan secara manual dengan tenaga manusia. Hal ini membuat permasalahan yaitu kualitas mutu bunga cengkeh kering yang tercampur dengan mutu lain. Karena hanya mengandalkan keterampilan dan ketelitian dari tenaga manusia. Kajian ilmu yang membahas tentang klasifikasi mutu cengkeh sudah banyak dilakukan, namun masih memiliki kekurangan berupa jumlah sampel yang digunakan masih sedikit dan proses klasifikasi yang membutuhkan waktu yang lama. Oleh karena itu, pada penelitian ini akan mengklasifikasi cengkeh dengan menggunakan metode Deep Convolutional Neural Network (DCNN) yang dapat mengolah data berjumlah besar serta proses klasifikasi yang lebih cepat tanpa melakukan ekstraksi data gambar. Penelitian ini bertujuan untuk membuat model CNN untuk klasifikasi mutu cengkeh produk dari PTPN 12 Kabupaten Malang, menganalisis parameter dalam pembuatan model CNN dan menguji performansi model CNN dalam mengklasifikasi mutu cengkeh. Pada penelitian ini menggunakan 4 klasifikasi mutu produk PTPN 12 yaitu kuncup 1, kuncup 2, biji mati dan polong. Dengan jumlah keseluruhan data gambar yang digunakan sebanyak 1600 gambar yang dibagi menjadi 900 data training, 300 data validasi dan 400 data testing. Data training dan data validasi digunakan untuk membuat model CNN, sedangkan data testing digunakan untuk menguji akurasi model CNN. Dalam pembuatan arsitektur CNN dilakukan analisis yaitu hyperparameter CNN atau analisa sensitivitas. Parameter arsitektur CNN yang dianalisis yaitu epoch, jumlah layer, ukuran gambar, ukuran kernel, strides, padding, dropout dan learning rate. Nilai terbaik pada setiap parameter akan digunakan dalam membuat arsitektur CNN. Kemudian dilakukan pengujian model CNN menggunakan data testing. Berdasarkan hasil penelitian didapatkan nilai parameter arsitektur CNN. Pada pengujian nilai epoch mencapai konvergen yaitu epoch 1300. Pengujian jumlah layer didapatkan akurasi terbaik dimiliki oleh penggunaan 2 layer dengan 32 dan 64 feature maps. Pengujian ukuran input gambar didapatkan nilai akurasi terbaik pada ukuran gambar 128×128 pixel. Pengujian ukuran kernel diperoleh akurasi terbaik pada ukuran 5×5 pixel. Pengujian nilai stride atau langkah, didapatkan nilai akurasi terbaik pada nilai 1×1 pixel. Pengujian pengaruh penggunaan padding, didapatkan akurasi terbaik pada penggunaan padding. Pengujian nilai dropout, didaptkan pada nilai dropout 0,4 yang memiliki akurasi terbaik. Pengujian learning rate, akurasi terbaik pada learning rate sebesar 0,0001. Parameter tersebut kemudian diujikan menggunakan data testing yang menghasilkan akurasi sebesar 87,75

딥러닝 기반 고장 진단을 위한 정보 활용 극대화 기법 개발

학위논문(박사) -- 서울대학교대학원 : 공과대학 기계항공공학부, 2021.8. 윤병동.기계 시스템의 예기치 않은 고장은 많은 산업 분야에서 막대한 사회적, 경제적 손실을 야기할 수 있다. 갑작스런 고장을 감지하고 예방하여 기계 시스템의 신뢰성을 높이기 위해 데이터 기반 고장 진단 기술을 개발하기 위한 연구가 활발하게 이루어지고 있다. 고장 진단 기술의 목표는 대상 기계 시스템의 고장 발생을 가능한 빨리 감지하고 진단하는 것이다. 최근 합성곱 신경망 기법을 포함한 딥러닝 기반 고장 진단 기술은 자율적인 특성인자(feature) 학습이 가능하고 높은 진단 성능을 얻을 수 있다는 장점이 있어 활발히 연구되고 있다. 그러나 딥러닝 기반의 고장 진단 기술을 개발함에 있어 해결해야 할 몇 가지 문제점들이 존재한다. 먼저, 신경망 구조를 깊게 쌓음으로써 풍부한 계층적 특성인자들을 배울 수 있고, 이를 통해 향상된 성능을 얻을 수 있다. 그러나 기울기(gradient) 정보 흐름의 비효율성과 과적합 문제로 인해 모델이 깊어질수록 학습이 어렵게 된다는 문제가 있다. 다음으로, 높은 성능의 고장 진단 모델을 학습하기 위해서는 충분한 양의 레이블 데이터(labeled data)가 확보돼야 한다. 그러나 실제 현장에서 운용되고 있는 기계 시스템의 경우, 충분한 양의 데이터와 레이블 정보를 얻는 것이 어려운 경우가 많다. 따라서 이러한 문제들을 해결하고 진단 성능을 향상시키기 위한 새로운 딥러닝 기반 고장 진단 기술의 개발이 필요하다. 본 박사학위논문에서는 딥러닝 기반 고장 진단 기술의 성능을 향상시키기 위한 세가지 정보 활용 극대화 기법에 대한 연구로 1) 딥러닝 아키텍처 내 기울기 정보 흐름을 향상시키기 위한 새로운 딥러닝 구조 연구, 2) 파라미터 전이 및 삼중항 손실을 기반으로 불충분한 데이터 및 노이즈 조건 하 강건하고 차별적인 특성인자 학습에 대한 연구, 3) 다른 도메인으로부터 레이블 정보를 전이시켜 사용하는 도메인 적응 기반 고장 진단 기법 연구를 제안한다. 첫 번째 연구에서는 딥러닝 모델 내 기울기 정보 흐름을 개선하기 위한 향상된 합성곱 신경망 기반 구조를 제안한다. 본 연구에서는 다양한 계층의 아웃풋(feature map)을 직접 연결함으로써 향상된 정보 흐름을 얻을 수 있으며, 그 결과 진단 모델을 효율적으로 학습하는 것이 가능하다. 또한 차원 축소 모듈을 통해 학습 파라미터 수를 크게 줄임으로써 학습 효율성을 높일 수 있다. 두 번째 연구에서는 파라미터 전이 및 메트릭 학습 기반 고장 진단 기법을 제안한다. 본 연구는 데이터가 불충분하고 노이즈가 많은 조건 하에서도 높은 고장 진단 성능을 얻기 위해 강건하고 차별적인 특성인자 학습을 가능하게 한다. 먼저, 풍부한 소스 도메인 데이터를 사용해 훈련된 사전학습모델을 타겟 도메인으로 전이해 사용함으로써 강건한 진단 방법을 개발할 수 있다. 또한, semi-hard 삼중항 손실 함수를 사용함으로써 각 상태 레이블에 따라 데이터가 더 잘 분리되도록 해주는 특성인자를 학습할 수 있다. 세 번째 연구에서는 레이블이 지정되지 않은(unlabeled) 대상 도메인에서의 고장 진단 성능을 높이기 위한 레이블 정보 전이 전략을 제안한다. 우리가 목표로 하는 대상 도메인에서의 고장 진단 방법을 개발하기 위해 다른 소스 도메인에서 얻은 레이블 정보가 전이되어 활용된다. 동시에 새롭게 고안한 의미론적 클러스터링 손실(semantic clustering loss)을 여러 특성인자 수준에 적용함으로써 차별적인 도메인 불변 기능을 학습한다. 결과적으로 도메인 불변 특성을 가지며 의미론적으로 잘 분류되는 특성인자를 효과적으로 학습할 수 있음을 증명하였다.Unexpected failures of mechanical systems can lead to substantial social and financial losses in many industries. In order to detect and prevent sudden failures and to enhance the reliability of mechanical systems, significant research efforts have been made to develop data-driven fault diagnosis techniques. The purpose of fault diagnosis techniques is to detect and identify the occurrence of abnormal behaviors in the target mechanical systems as early as possible. Recently, deep learning (DL) based fault diagnosis approaches, including the convolutional neural network (CNN) method, have shown remarkable fault diagnosis performance, thanks to their autonomous feature learning ability. Still, there are several issues that remain to be solved in the development of robust and industry-applicable deep learning-based fault diagnosis techniques. First, by stacking the neural network architectures deeper, enriched hierarchical features can be learned, and therefore, improved performance can be achieved. However, due to inefficiency in the gradient information flow and overfitting problems, deeper models cannot be trained comprehensively. Next, to develop a fault diagnosis model with high performance, it is necessary to obtain sufficient labeled data. However, for mechanical systems that operate in real-world environments, it is not easy to obtain sufficient data and label information. Consequently, novel methods that address these issues should be developed to improve the performance of deep learning based fault diagnosis techniques. This dissertation research investigated three research thrusts aimed toward maximizing the use of information to improve the performance of deep learning based fault diagnosis techniques, specifically: 1) study of the deep learning structure to enhance the gradient information flow within the architecture, 2) study of a robust and discriminative feature learning method under insufficient and noisy data conditions based on parameter transfer and triplet loss, and 3) investigation of a domain adaptation based fault diagnosis method that propagates the label information across different domains. The first research thrust suggests an advanced CNN-based architecture to improve the gradient information flow within the deep learning model. By directly connecting the feature maps of different layers, the diagnosis model can be trained efficiently thanks to enhanced information flow. In addition, the dimension reduction module also can increase the training efficiency by significantly reducing the number of trainable parameters. The second research thrust suggests a parameter transfer and metric learning based fault diagnosis method. The proposed approach facilitates robust and discriminative feature learning to enhance fault diagnosis performance under insufficient and noisy data conditions. The pre-trained model trained using abundant source domain data is transferred and used to develop a robust fault diagnosis method. Moreover, a semi-hard triplet loss function is adopted to learn the features with high separability, according to the class labels. Finally, the last research thrust proposes a label information propagation strategy to increase the fault diagnosis performance in the unlabeled target domain. The label information obtained from the source domain is transferred and utilized for developing fault diagnosis methods in the target domain. Simultaneously, the newly devised semantic clustering loss is applied at multiple feature levels to learn discriminative, domain-invariant features. As a result, features that are not only semantically well-clustered but also domain-invariant can be effectively learned.Chapter 1 Introduction 1 1.1 Motivation 1 1.2 Research Scope and Overview 3 1.3 Dissertation Layout 6 Chapter 2 Technical Background and Literature Review 8 2.1 Fault Diagnosis Techniques for Mechanical Systems 8 2.1.1 Fault Diagnosis Techniques 10 2.1.2 Deep Learning Based Fault Diagnosis Techniques 15 2.2 Transfer Learning 22 2.3 Metric Learning 28 2.4 Summary and Discussion 30 Chapter 3 Direct Connection Based Convolutional Neural Network (DC-CNN) for Fault Diagnosis 31 3.1 Directly Connected Convolutional Module 33 3.2 Dimension Reduction Module 34 3.3 Input Vibration Image Generation 36 3.4 DC-CNN-Based Fault Diagnosis Method 40 3.5 Experimental Studies and Results 45 3.5.1 Experiment and Data Description 45 3.5.2 Compared Methods 48 3.5.3 Diagnosis Performance Results 51 3.5.4 The Number of Trainable Parameters 56 3.5.5 Visualization of the Learned Features 58 3.5.6 Robustness of Diagnosis Performance 62 3.6 Summary and Discussion 67 Chapter 4 Robust and Discriminative Feature Learning for Fault Diagnosis Under Insufficient and Noisy Data Conditions 68 4.1 Parameter transfer learning 70 4.2 Robust Feature Learning Based on the Pre-trained model 72 4.3 Discriminative Feature Learning Based on the Triplet loss 77 4.4 Robust and Discriminative Feature Learning for Fault Diagnosis 80 4.5 Experimental Studies and Results 84 4.5.1 Experiment and Data Description 84 4.5.2 Compared Methods 85 4.5.3 Experimental Results Under Insufficient Data Conditions 86 4.5.4 Experimental Results Under Noisy Data Conditions 92 4.6 Summary and Discussion 95 Chapter 5 A Domain Adaptation with Semantic Clustering (DASC) Method for Fault Diagnosis 96 5.1 Unsupervised Domain Adaptation 101 5.2 CNN-based Diagnosis Model 104 5.3 Learning of Domain-invariant Features 105 5.4 Domain Adaptation with Semantic Clustering 107 5.5 Proposed DASC-based Fault Diagnosis Method 109 5.6 Experimental Studies and Results 114 5.6.1 Experiment and Data Description 114 5.6.2 Compared Methods 117 5.6.3 Scenario I: Different Operating Conditions 118 5.6.4 Scenario II: Different Rotating Machinery 125 5.6.5 Analysis and Discussion 131 5.7 Summary and Discussion 140 Chapter 6 Conclusion 141 6.1 Contributions and Significance 141 6.2 Suggestions for Future Research 143 References 146 국문 초록 154박

Optimisation of microfluidic experiments for model calibration of a synthetic promoter in S. cerevisiae

This thesis explores, implements, and examines the methods to improve the efficiency of model calibration experiments for synthetic biological circuits in three aspects: experimental technique, optimal experimental design (OED), and automatic experiment abnormality screening (AEAS). Moreover, to obtain a specific benchmark that provides clear-cut evidence of the utility, an integrated synthetic orthogonal promoter in yeast (S. cerevisiae) and a corresponded model is selected as the experiment object. This work first focuses on the “wet-lab” part of the experiment. It verifies the theoretical benefit of adopting microfluidic technique by carrying out a series of in-vivo experiments on a developed automatic microfluidic experimental platform. Statistical analysis shows that compared to the models calibrated with flow-cytometry data (a representative traditional experimental technique), the models based on microfluidic data of the same experiment time give significantly more accurate behaviour predictions of never-encountered stimuli patterns. In other words, compare to flow-cytometry experiments, microfluidics can obtain models of the required prediction accuracy within less experiment time. The next aspect is to optimise the “dry-lab” part, i.e., the design of experiments and data processing. Previous works have proven that the informativeness of experiments can be improved by optimising the input design (OID). However, the amount of work and the time cost of the current OID approach rise dramatically with large and complex synthetic networks and mathematical models. To address this problem, this thesis introduces the parameter clustering analysis and visualisation (PCAV) to speed up the OID by narrowing down the parameters of interest. For the first time, this thesis proposes a parameter clustering algorithm based on the Fisher information matrix (FIMPC). Practices with in-silico experiments on the benchmarking promoter show that PCAV reduces the complexity of OID and provides a new way to explore the connections between parameters. Moreover, the analysis shows that experiments with FIMPC-based OID lead to significantly more accurate parameter estimations than the current OID approach. Automatic abnormality screening is the third aspect. For microfluidic experiments, the current identification of invalid microfluidic experiments is carried out by visual checks of the microscope images by experts after the experiments. To improve the automation level and robustness of this quality control process, this work develops an automatic experiment abnormality screening (AEAS) system supported by convolutional neural networks (CNNs). The system learns the features of six abnormal experiment conditions from images taken in actual microfluidic experiments and achieves identification within seconds in the application. The training and validation of six representative CNNs of different network depths and design strategies show that some shallow CNNs can already diagnose abnormal conditions with the desired accuracy. Moreover, to improve the training convergence of deep CNNs with small data sets, this thesis proposes a levelled-training method and improves the chance of convergence from 30% to 90%. With a benchmark of a synthetic promoter model in yeast, this thesis optimises model calibration experiments in three aspects to achieve a more efficient procedure: experimental technique, optimal experimental design (OED), and automatic experiment abnormality screening (AEAS). In this study, the efficiency of model calibration experiments for the benchmarking model can be improved by: adopting microfluidics technology, applying CAVP parameter analysis and FIMPC-based OID, and setting up an AEAS system supported by CNN. These contributions have the potential to be exploited for designing more efficient in-vivo experiments for model calibration in similar studies