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Jesus Carretero

Publications and source records attributed to Jesus Carretero.

6 recordsLinked to original sources

Characterizing the I/O Behavior of HPC Applications through Modeling and Simulation

Parallel applications process large amounts of data, leading to intensive parallel I/O operations. These operations can exhibit different levels of complexity, including, among others, multiple I/O access patterns, data staging, and contention risks. Therefore, in order to exploit high-performance computing (HPC) systems efficiently and optimize the I/O performance, it is crucial to consider the I/O behaviour of the HPC applications. In this work, we have developed a framework that reproduces the I/O access pattern of real applications in a simulated environment provided by ElastiSim, a batch-system simulator for rigid, malleable, and evolving workloads. The simulated applications are generated based on I/O traces captured from real applications provided by the HPC Input/Output (HPCIO) analysis repository. The HPCIO analysis database includes traces combined with information about real applications' performance across different parallel I/O libraries and layers of the I/O stack. We have conducted detailed case studies of real-world applications' traces to demonstrate how the proposed modeling framework can provide insights into the performance characteristics of I/O applications, including the I/O congestion analysis based on the application's I/O access pattern.

cs.DC

OsteoCAD: A Human-in-the-Loop Cloud-Edge Framework for Bone Tumor Segmentation

Artificial Intelligence (AI) and Deep Learning (DL) have notably advanced medical image analysis, yet many health- care organizations struggle to adopt them due to limited com- putational resources and specialized expertise. To address these barriers, we introduce OsteoCAD, a modular eHealth framework that democratizes access to DL tools in clinical practice. Osteo- CAD delivers end-to-end DL capabilities-from dataset creation and preprocessing to model training and inference-through an integrated and user-friendly interface. To mitigate local hardware constraints, the framework securely connects to remote GPU infrastructures. We validate OsteoCAD's feasibility through a real-world case study in Mexico focused on large bone tumor segmentation. The results demonstrate the framework's ability to enable DL-powered eHealth solutions without demanding ad- vanced technical expertise or complex local configurations.

cs.CV

A Computer-aided Framework for Detecting Osteosarcoma in Computed Tomography Scans

Osteosarcoma is the most common primary bone cancer, mainly affecting the youngest and oldest populations. Its detection at early stages is crucial to reduce the probability of developing bone metastasis. In this context, accurate and fast diagnosis is essential to help physicians during the prognosis process. The research goal is to automate the diagnosis of osteosarcoma through a pipeline that includes the preprocessing, detection, postprocessing, and visualization of computed tomography (CT) scans. Thus, this paper presents a machine learning and visualization framework for classifying CT scans using different convolutional neural network (CNN) models. Preprocessing includes data augmentation and identification of the region of interest in scans. Post-processing includes data visualization to render a 3D bone model that highlights the affected area. An evaluation on 12 patients revealed the effectiveness of our framework, obtaining an area under the curve (AUC) of 94.8\% and a specificity of 94.6\%.

cs.CV

DynoStore: A wide-area distribution system for the management of data over heterogeneous storage

Data distribution across different facilities offers benefits such as enhanced resource utilization, increased resilience through replication, and improved performance by processing data near its source. However, managing such data is challenging due to heterogeneous access protocols, disparate authentication models, and the lack of a unified coordination framework. This paper presents DynoStore, a system that manages data across heterogeneous storage systems. At the core of DynoStore are data containers, an abstraction that provides standardized interfaces for seamless data management, irrespective of the underlying storage systems. Multiple data container connections create a cohesive wide-area storage network, ensuring resilience using erasure coding policies. Furthermore, a load-balancing algorithm ensures equitable and efficient utilization of storage resources. We evaluate DynoStore using benchmarks and real-world case studies, including the management of medical and satellite data across geographically distributed environments. Our results demonstrate a 10\% performance improvement compared to centralized cloud-hosted systems while maintaining competitive performance with state-of-the-art solutions such as Redis and IPFS. DynoStore also exhibits superior fault tolerance, withstanding more failures than traditional systems.

cs.DC

D-Rex: Heterogeneity-Aware Reliability Framework and Adaptive Algorithms for Distributed Storage

The exponential growth of data necessitates distributed storage models, such as peer-to-peer systems and data federations. While distributed storage can reduce costs and increase reliability, the heterogeneity in storage capacity, I/O performance, and failure rates of storage resources makes their efficient use a challenge. Further, node failures are common and can lead to data unavailability and even data loss. Erasure coding is a common resiliency strategy implemented in storage systems to mitigate failures by striping data across storage locations. However, erasure coding is computationally expensive and existing systems do not consider the heterogeneous resources and their varied capacity and performance when placing data chunks. We tackle the challenges of using erasure coding with distributed and heterogeneous nodes, aiming to store as much data as possible, minimize encoding and decoding time, and meeting user-defined reliability requirements for each data item. We propose two new dynamic scheduling algorithms, D-Rex LB and D-Rex SC, that adaptively choose erasure coding parameters and map chunks to heterogeneous nodes. D-Rex SC achieves robust performance for both storage utilization and throughput, at a higher computational cost, while D-Rex LB is faster but with slightly less competitive performance. In addition, we propose two greedy algorithms, GreedyMinStorage and GreedyLeastUsed, that optimize for storage utilization and load balancing, respectively. Our experimental evaluation shows that our dynamic schedulers store, on average, 45% more data items without significantly degrading I/O throughput compared to state-of-the-art algorithms, while GreedyLeastUsed is able to store 21% more data items while also increasing throughput.

cs.DC

GeoNimbus: A serverless framework to build earth observation and environmental services

Cloud computing has become a popular solution for organizations implementing Earth Observation Systems (EOS). However, this produces a dependency on provider resources. Moreover, managing and executing tasks and data in these environments are challenges that commonly arise when building an EOS. This paper presents GeoNimbus, a serverless framework for composing and deploying spatio-temporal EOS on multiple infrastructures, e.g., on-premise resources and public or private clouds. This framework organizes EOS tasks as functions and automatically manages their deployment, invocation, scalability, and monitoring in the cloud. GeoNimbus framework enables organizations to reuse and share available functions to compose multiple EOS. We use this framework to implement EOS as a service for conducting a case study focused on measuring water resource changes in a lake in the south of Mexico. The experimental evaluation revealed the feasibility and efficiency of using GeoNimbus to build different earth observation studies.

cs.DC