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PublicationAdvances in Host Plant and Rhizobium Genomics to Enhance Symbiotic Nitrogen Fixation inGrain Legumes( 2015-01-01)
;Dwivedi S.L. ;Sahrawat K.L. ;Upadhyaya H.D. ;Mengoni A. ;Galardini M. ;Bazzicalupo M. ;Biondi E.G. ;Hungria M. ;Kaschuk G. ;Blair M.W.Ortiz R.Legumes form symbiotic relationship with root-nodule, rhizobia. The nitrogen (N2) fixed by legumes is a renewable source and of great importance to agriculture. Symbiotic nitrogen fixation (SNF) is constrained by multiple stresses and alleviating them would improve SNF contribution to agroecosystems. Genetic differences in adaptation tolerance to various stresses are known in both host plant and rhizobium. The discovery and use of promiscuous germplasm in soybean led to the release of high-yielding cultivars in Africa. High N2-fixing soybean cultivars are commercially grown in Australia and some countries in Africa and South America and those of pea in Russia. SNF is a complex trait, governed by multigenes with varying effects. Few major quantitative trait loci (QTL) and candidate genes underlying QTL are reported in grain and model legumes. Nodulating genes in model legumes are cloned and orthologs determined in grain legumes. Single nucleotide polymorphism (SNP) markers from nodulation genes are available in common bean and soybean. Genomes of chickpea, pigeonpea, and soybean; and genomes of several rhizobium species are decoded. Expression studies revealed few genes associated with SNF in model and grain legumes. Advances in host plant and rhizobium genomics are helping identify DNA markers to aid breeding of legume cultivars with high symbiotic efficiency. A paradigm shift is needed by breeding programs to simultaneously improve host plant and rhizobium to harness the strength of positive symbiotic interactions in cultivar development. Computation models based on metabolic reconstruction pathways are providing greater insights to explore genotype-phenotype relationships in SNF. Models to simulate the response of N2 fixation to a range of environmental variables and crop growth are assisting researchers to quantify SNF for efficient and sustainable agricultural production systems. Such knowledge helps identifying bottlenecks in specific legume-rhizobia systems that could be overcome by legume breeding to enhance SNF. This review discusses the recent developments to improve SNF and productivity of grain legumes. -
PublicationB-EDCA: A new IEEE 802.11e-based QoS protocol for multimedia wireless communications( 2006-01-01)
;Villaón J. ;Cuenca P.The IEEE 802.11e draft standard is a proposal defining the mechanisms for wireless LANs aiming to provide QoS support to time-sensitive applications. However, recent studies have shown that the IEEE 802.11e (EDCA) performs poorly when the medium is highly loaded due to the high collision rate. Even though several proposals have been proposed to address this problem, they require important changes to the current standard specifications making difficult their actual implementation. In this paper, we propose a simple QoS-aware mechanism and fully compatible with the various operation modes of the EDCA standard as well as the legacy IEEE 802.11 (DCF) scheme. Our design has been based on an in-depth analysis of the several operation modes of both standards. This should ensure full compatibility of operation: an important feature since the transition from the IEEE 802.11 to the IEEE 802.11e will take some time making more likely the existence of hybrid scenarios where both standards will have to coexist. Our simulation results show that our new scheme outperforms the EDCA and other QoS-aware schemes recently reported in the literature. © IFIP International Federation for Information Processing 2006. -
PublicationConventional banana and plantain breeding( 2013-04-25)Ortiz R.Cross-breeding of banana and plantain brings new challenges to the genetic improvement of crops due to the ploidy and high sterility of most popular cultivars. This article provides an overview of the current status of banana and plantain breeding. It also provides details on the approaches used and steps throughout the breeding process: crossing, screening, testing, selecting and identifying promising hybrids for further cultivar releases. This manuscript also highlights the genetic knowledge accumulated in this crop that will facilitate the use of new approaches in its improvement. Banana and plantain breeding programs may incorporate genetic engineering and genomics-led breeding to enhance their effectiveness, particularly under a changing climate that is likely to affect crop yields.
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PublicationEfficiently mining gapped and window constraint frequent sequential patterns( 2020-01-01)
;Guevara-Cogorno A. ;Maehara Y.Sequential pattern mining is one of the most widespread data mining tasks with several real-life decision-making applications. In this mining process, constraints were added to improve the mining efficiency for discovering patterns meeting specific user requirements. Therefore, the temporal constraints, in particular, those that arise from the implicit temporality of sequential patterns, will have the ability to efficiently apply temporary restrictions such as, window and gap constraints. In this paper, we propose a novel window and gap constrained algorithms based on the well-known PrefixSpan algorithm. For this purpose, we introduce the virtual multiplication operation aiming for a generalized window mining algorithm that preserves other constraints. We also extend the PrefixSpan Pseudo-Projection algorithm to mining patterns under the gap-constraint. Our performance study shows that these extensions have the same time complexity as PrefixSpan and good linear scalability. -
PublicationErratum: Platalina genovensium (Chiroptera: Phyllostomidae) (Mammalian Species 52:995 (1-9) DOI: 10.1093/mspecies/seaa008)( 2020-12-15)
;Ossa G.Velazco P.M.The originally published version of this manuscript contained two errors that are listed in this corrigendum. The Acknowledgments should read: "We are grateful to N. Simmons (American Museum of Natural History) for access to specimens of Platalina. We also thank two anonymous reviewers during the peer view process." Upon original publication, Figure 4 was incorrect and should be updated as follows: These errors have now been corrected with this corrigendum. The author would like to apologize for the errors. Nomenclatural statement.-A Life Science Identifier (LSID) number was obtained for this publication: urn:lsid:zoobank.org:pub: EAEADBC7-04B3-44FB-BAC9-428ADD3C9FEA. -
PublicationLean Manufacturing Application in the Laminating Machine Manufacturing Process in a Metalworking Company(Springer Science and Business Media Deutschland GmbH, 2021-01-01)
;Camacho Sanchez K.E. ;Saavedra Rosales J.J. ;Salvatierra Garcia Y.This study describes an improvement implementation in the manufacturing process of a laminating machine using lean manufacturing tools. After identifying the activities that do not add value to the process, the Ishikawa diagram and Pareto diagram were applied to determine the potential causes of it. Finally, the visual board, the 5 S, and the poka-yoke were successfully implemented, achieving a 25-day reduction in the manufacturing process time, which represents an efficiency of 36.57%. -
PublicationMedical equipment maintenance support with service-oriented multi-agent services( 2012-12-01)
;Lopez B. ;Pla A. ;Daroca D. ;Lozano S.Meléndez J.Service oriented architectures (SOA) have emerged as an approach to handle the complexity of enterprise interoperability. Recently, multi-agent systems have been promoted as a technique to deal with cooperation issues involved in SOA. This cooperation is particularly important in several application domains, in which different companies are involved in a concrete service deployment. Agents, among other issues, offer the possibility to decide, if more than one option is available, providing flexibility and robustness. In this paper, we describe the agent-based cooperation process we have followed to enable partner's cooperation in an equipment maintenance workflow. The use of ontologies and relationships with standards is highlighted. The approach is illustrated in an hospital scenario considered in the AIMES project. © Springer-Verlag Berlin Heidelberg 2012. -
PublicationMOOCs in Logistics – Preliminary Data on University Curricula Coverage( 2021-01-01)
;Niine T. ;Cantoni F.After a decade of MOOC and open education development there is an abundance of available online content. The aim of this study is to find out whether the MOOC landscape in logistics has grown to a point of topically covering entire university curricula worth of topics. Provided the affirmative outcome, this would mean greater competition but also greater opportunities for universities teaching logistics programs to apply blended learning. We present an overview of logistics-related material on three major platforms totaling 95 courses and compare a sample of five logistics curricula against this list to demonstrate the extent of coverage by online material as well as to point out the gaps. The data suggests that the current status of logistics MOOCs can mostly cover more introductory and broader managerial-type programs but not material on logistics operations in-depth. Also, MOOCs tend to struggle with more interdisciplinary topic approaches. The findings allow to discuss on the nature of identified gaps as well as to encourage and foresee continuous growth of blended learning. -
PublicationPlatalina genovensium (Chiroptera: Phyllostomidae)( 2020-12-15)
;Ossa G.Velazco P.M.Platalina genovensium Thomas, 1928 is a bat commonly called Peruvian long-tongued bat. P. genovensium is characterized by having a greatly elongated muzzle, rostrum clearly longer than the braincase, and premaxillary bones projecting beyond the canines. The dorsal pelage is long and bicolored; the venter is lighter than the dorsum. P. genovensium is distributed from west of the Andes in Peru to northern Chile, with a few records reported from the Andes in Peru. It feeds in desert areas characterized by the presence of columnar cacti from which it obtains nectar and fruits; it has been recorded at elevations from near sea level up to about 2,600 m. It is listed as “Near Threatened” by the International Union for Conservation of Nature and Natural Resources. -
PublicationPreface(Springer Science and Business Media Deutschland GmbH, 2022-01-01)
;Emrouznejad A. -
PublicationProbability TheoryProbability theory is a branch of mathematical science that deals with the mathematical analysis of random events. Probability is commonly used to describe the mind’s attitude to statements that we are not sure of. Statements usually take the form of “Will a particular event occur?” and the attitude of our minds will be of the form “How confident are we that this event will occur?” Our confidence can be described numerically, which is a value between 0 and 1 that we call probability. The more likely to occur an event is, the more confident we are that it will occur. The focus in this chapter is mainly on probability space, random variable, multi-dimensional probability distribution, expected value, variance, and covariance.
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PublicationSeismic Assessment of the Church of San Sebastian in Cusco, Peru by Means of Pushover Nonlinear Analysis(Springer Netherlands, 2019)
;Moreira S.The present paper seeks to evaluate the seismic performance of the San Sebastian church and its vulnerability to seismic events. This colonial temple dates back to the 16th century and is located in Cusco, Perú. The church stands out for being one of the first five Andean temples erected in the city of Cusco and also for being one of the most outstanding expressions of baroque art. Due to its artistic and cultural value, this church was declared National Cultural Heritage in 1972. Unfortunately, the periodic occurrence of seismic events and a fateful fire occurred in 2016 have endangered the survival of the structure and the safety of visitors. Aiming to evaluate the current situation of the church, this research developed a pathological identification through visual inspection and IR thermography as a non-destructive technique. A numerical analysis was also performed by means of a nonlinear pushover analysis that allowed estimating the evolution of the damage and the capacity of the structure in a seismic event. The results of the analysis showed that the main failure mechanisms of the structure would be the decoupling of the church front portion (towers and choir), generating concentrated damage in the arches that support the choir, as well as longitudinal cracks in the nave walls. The seismic capacity related to these failures is around 0.20Â g, which is much lower than the recommended demand from the Peruvian code for the region of Cusco – 0.25Â g – meaning that the church is highly vulnerable to seismic loads. -
PublicationSemantic Segmentation of Underwater Environments Using DeepLabv3+ and Transfer Learning( 2022-01-01)
;Chicchon M.The semantic segmentation approach is essential in automated scene analysis, but its application in underwater environments is still limited. Datasets generally have insufficient labeled data, unbalanced data classes, and different lighting conditions, making it difficult to obtain optimal results. Currently, deep convolutional neural networks allow very good results in machine vision tasks, and one of the network architectures with good performance in semantic segmentation is DeepLabv3 +. This paper evaluates the performance of DeepLabv3 + and transfer learning based on pre-trained backend networks in ImageNet to study underwater scenes. The experimentation is carried out on a dataset available on the Internet with labels of eight classes. Experimental results show that DeepLabv3 + and transfer learning are effective for semantic segmentation of multiple underwater scene objects with insufficient tagged data and unbalanced classes. -
PublicationSemantic Segmentation of Weeds and Crops in Multispectral Images by Using a Convolutional Neural Networks Based on U-Net( 2020-01-01)
;Chicchón Apaza M.Á.Garrido R.P.A.A first step in the process of automating weed removal in precision agriculture is the semantic segmentation of crops, weeds and soil. Deep learning techniques based on convolutional neural networks are successfully applied today and one of the most popular network architectures in semantic segmentation problems is U-Net. In this article, the variants in the U-Net architecture were evaluated based on the aggregation of residual and recurring blocks to improve their performance. For training and testing, a set of data available on the Internet was used, consisting of 60 multispectral images with unbalanced pixels, so techniques were applied to increase and balance the data. Experimental results show a slight increase in quality metrics compared to the classic U-Net architecture. -
PublicationSolid rocket motor design optimization using genetic algorithm( 2014-01-01)
;He L.S.Xu D.J.A design optimization approach of a solid propellant rocket motor is considered. A genetic algorithm (GA) optimization method has been used. The optimized solid rocket motor (SRM) is intended to use as a booster of a flight vehicle, and delivering a specific payload following a predefined prescribed trajectory. Sensitivity analysis of the optimized solution has been conducted using Monte Carlo method to evaluate the effect of uncertainties in design parameters. The results show that the proposed optimization approach was able to find the convergence of the optimal solution with highly acceptable value for conceptual design phase. © (2014) Trans Tech Publications, Switzerland. -
PublicationState of the World's Amphibians( 2015-11-04)The Anthropocene is characterized by a widespread biodiversity crisis that is rivaling prehistoric mass extinctions. Amphibians are the most threatened class of vertebrates. In addition to traditional threats such as land-use conversion and pollution, climate change and introduced diseases are expected to further reduce amphibian biodiversity. The fungal disease chytridiomycosis has caused the rapid extirpation of tens to possibly hundreds of amphibian species. Recent advances have revealed a deep evolutionary history and considerable variation in the virulence of strains of the fungal pathogen, patterns that need to be reconciled with the rapid spread of disease and demise of host populations. A conservation priority is surveillance of a newly discovered species of chytrid fungus that is killing European salamanders. The accelerated discovery of new amphibian species challenges existing conservation resources, but it is an opportunity to fill geographical gaps and to enhance programs aimed at preserving amphibian biodiversity.
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PublicationSynthesis of multicomponent reuse water networks by PSO approach( 2014-01-01)
;Ravagnani M. ;Trigueros D. ;Módenes A.In the present paper the problem of reuse water networks (RWN) have been modeled and optimized by the application of a modified Particle Swarm Optimization (PSO) algorithm. A proposed modified PSO method lead with both discrete and continuous variables in Mixed Integer Non-Linear Programming (MINLP) formulation that represent the water allocation problems. Pinch Analysis concepts are used jointly with the improved PSO method. Two literature problems considering mono and multicomponent problems were solved with the developed systematic and results has shown excellent performance in the optimality of reuse water network synthesis based on the criterion of minimization of annual total cost. -
PublicationTerahertz Imaging and Machine Learning in the Classification of Coffee Beans(Springer Science and Business Media Deutschland GmbH, 2021-01-01)
;Yoshida H.Castillo P.The geographical origin of coffee beans represents an effect on the attributes and quality of the product due to the different soil and weather conditions for a specific location. Therefore, the development of methods for rapid classification and authentication of coffee beans based on their geographical origin is essential. This research was done with the purpose of determining the capacity of coffee (Coffea arabica) varieties classification with the use of Terahertz (THz) imaging and machine learning. THz images of coffee beans samples from 3 different geographical origins were acquired with a time-domain spectrometer and then used to measure the classification performance of methods such as neural networks, random forests, and support vector machines. The results obtained reached an accuracy up to 91.2%, which showed that the use of THz imaging and machine learning is an effective method for the non-destructive analysis of coffee variables and classification based on geographical origin. -
PublicationThe effect of pre-culture temperature treatment on the cryopreservation of potato shoot-tips(International Society for Horticultural Science, 2011-09-30)
;Tay D. ;Ynouye C.The International Potato Center's (CIP) genebank was established following its foundation in 1971. Currently, 4,607 accessions of 7 cultivated potato species are maintained clonally as tuber, in vitro, cryo- and DNA collections in CIP genebank. In January 2008, CIP's genebank became the first worldwide to obtain an ISO 17025 accreditation for its in vitro germplasm conservation and distribution systems. The cryo-bank is an integrated part of the total genebank safety backup management system. The vitrification protocol developed by Steponkus at Cornell University was applied to 400 potato genotypes, and 121 accessions were successfully cryopreserved. During 2004-2006, with an aim of establishing a cryo-bank for a long-term conservation of potato landraces, research for improving cryo-procedures was conducted and as result a revised PVS2 vitrification method was developed. Currently, the droplet PVS2 vitrification method is the preferred procedure applied to place the 4,607 accessions of cultivated potatoes into the cryo-bank. Testing 434 potato accessions and using both, 6 and 22°C pre-culture treatments, 92% showed recovery frequency of at least 5%; out of them 67% reached at least 20% recovery. This protocol increased the range of genotypes showing positive post-thawing recovery, and rendered suitable for the long-term conservation of widely diverse potato genotypes, with shoot-tips' recovery rates of 20-100% in two replicated lots of 50 shoot-tips each. -
PublicationThe role of extension services for the successful introduction of new Musa cultivars in southeastern Nigeria(International Society for Horticultural Science, 2000-01-01)
;Akele S. ;Isirimah N. ;Brisibe A.Ortiz R.Black sigatoka causes yield losses of 30 to 50% in banana and plantain. The cultivation of resistant cultivars is the most appropriate intervention to control this fungal leaf spot disease in Africa. The short-term approach of the International Institute of Tropical Agriculture (IITA) to control black sigatoka in Nigeria was to identify, multiply and distribute resistant cooking bananas. The Green River Project (GRP), in collaboration with IITA, has been promoting cooking bananas as a substitute for plantain in southeastern Nigeria. Five rural areas in the northern part of Rivers State (Omoku/Kreigani, Obrikom-Obie-Obor-Ebeghoro, Ebocha, Mgbede/ Aggah and Okwuzi) are served by GRP. An extension officer and a rural assistant officer are responsible for transferring new techniques and cultivars to the farming community. Local farmers are regularly informed, through practical demonstrations, how to improve their current cultural practices and how to incorporate new products into their diets. Since local consumers were not accustomed to cooking bananas, the extension officers carried out palatability tests to show how this new product may be cooked and eaten. Farmers and consumers indicated that cooking bananas had smaller and softer fruits, longer cooking time and lower starch than plantains. Nonetheless, farmers are gradually accepting cooking bananas as substitute of plantain because of their resistance to black sigatoka. Hence, GRP has multiplication plots for further distribution of cooking banana suckers to farmers. The success for adoption of cooking bananas by the farming community in southeastern Nigeria will depend on creating public awareness and encouraging the planting of black sigatoka resistant cooking bananas among local farmers. This will need adequate extension services which should provide planting materials with high health status and proper technology for storage and enhanced utilization of cooking bananas after harvest. This experience with cooking bananas may provide means for a successful and fast distribution to the Nigerian farmers of new plantain or banana hybrid cultivars when they become available.