• Title/Summary/Keyword: Perez model

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An Approach to Art Collections Management and Content-based Recovery

  • De Celis Herrero, Concepcion Perez;Alvarez, Jaime Lara;Aguilar, Gustavo Cossio;Garcia, Maria Josefa Somodevilla
    • Journal of Information Processing Systems
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    • v.7 no.3
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    • pp.447-458
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    • 2011
  • This study presents a comprehensive solution to the collection management, which is based on the model for Cultural Objects (CCO). The developed system manages and spreads the collections that are safeguarded in museums and galleries more easily by using IT. In particular, we present our approach for a non-structured search and recovery of the objects based on the annotation of artwork images. In this methodology, we have introduced a faceted search used as a framework for multi-classification and for exploring/browsing complex information bases in a guided, yet unconstrained way, through a visual interface.

Supervised text data augmentation method for deep neural networks

  • Jaehwan Seol;Jieun Jung;Yeonseok Choi;Yong-Seok Choi
    • Communications for Statistical Applications and Methods
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    • v.30 no.3
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    • pp.343-354
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    • 2023
  • Recently, there have been many improvements in general language models using architectures such as GPT-3 proposed by Brown et al. (2020). Nevertheless, training complex models can hardly be done if the number of data is very small. Data augmentation that addressed this problem was more than normal success in image data. Image augmentation technology significantly improves model performance without any additional data or architectural changes (Perez and Wang, 2017). However, applying this technique to textual data has many challenges because the noise to be added is veiled. Thus, we have developed a novel method for performing data augmentation on text data. We divide the data into signals with positive or negative meaning and noise without them, and then perform data augmentation using k-doc augmentation to randomly combine signals and noises from all data to generate new data.

Nonlinear modeling of a RC beam-column connection subjected to cyclic loading

  • Dominguez, Norberto;Perez-Mota, Jesus
    • Computers and Concrete
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    • v.21 no.3
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    • pp.299-310
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    • 2018
  • When reinforced concrete structures are subjected to strong seismic forces, their beam-column connections are very susceptible to be damaged during the earthquake event. Consequently, structural designers try to fit an important quantity of steel reinforcement inside the connection, complicating its construction without a clear justification for this. The aim of this work is to evaluate -and demonstrate- numerically how the quantity and the array of the internal steel reinforcement influences on the nonlinear response of the RC beam-column connection. For this, two specimens (extracted from an experimental test of 12 RC beam-column connections reported in literature) were modeled in the Finite Element code FEAP considering different stirrup's arrays. The nonlinear response of the RC beam-column connection is evaluated taking into account the nonlinear thermodynamic behavior of each component: a damage model is used for concrete; a classical plasticity model is adopted for steel reinforcement; the steel-concrete bonding is considered perfect without degradation. At the end, the experimental responses obtained in the tests are compared to the numerical results, as well as the distribution of shear stresses and damage inside the concrete core of the beam-column connection, which are analyzed for a low and high state of confinement.

Mechanical verification logic and first test results for the Euclid spacecraft

  • Calvi, Adriano;Bastia, Patrizia;Suarez, Manuel Perez;Neumann, Philipp;Carbonell, Albert
    • Advances in aircraft and spacecraft science
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    • v.7 no.3
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    • pp.251-269
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    • 2020
  • Euclid is an optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the nature of dark energy, dark matter and gravity by observing the geometry of the Universe and the formation of structures over cosmological timescales. The Euclid spacecraft mechanical architecture comprises the Payload Module (PLM) and the Service Module (SVM) connected by an interface structure designed to maximize thermal and mechanical decoupling. This paper shortly illustrates the mechanical system of the spacecraft and the mechanical verification philosophy which is based on the Structural and Thermal Model (STM), built at flight standard for structure and thermal qualification and the Proto Flight Model (PFM), used to complete the qualification programme. It will be submitted to a proto-flight test approach and it will be suitable for launch and flight operations. Within the overall verification approach crucial mechanical tests have been successfully performed (2018) on the SVM platform and on the sunshield (SSH) subsystem: the SVM platform static test, the SSH structure modal survey test and the SSH sine vibration qualification test. The paper reports the objectives and the main results of these tests.

México: Ambiente, cultura y sociedad. Un análisis desde la perspectiva del modelo RECREA

  • Perez, Jose Isabel Juan;Michel, Gerardo Gomez
    • Iberoamérica
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    • v.22 no.2
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    • pp.153-179
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    • 2020
  • In the Mexican territory the cultural diversity is associated with the environmental diversity, this is demonstrated by the presence of native groups that inhabit the regions of the country, which are characterized by the management of various natural resources that they obtain from the terrestrial and aquatic environments of each of the regions. Through the RECREA Model: complex thinking, information and communication technologies and research-action, complemented with fundamentals of geography, environmental geography, cultural ecology, field work and cartographic information, we explained and analyzed the association between environmental diversity and cultural diversity to demonstrate that in Mexico there are still links between the environment, society and culture, a situation that determines the existence of human groups that subsist in the context of a global capitalist system that extracts in an unsustainable way natural resources. Based on these results, an instructional model is made to put it to practice with international students, in this case from Japan and South Korea, to allow the observation of its functionality in transmitting the aforementioned results on environmental and cultural diversity in Mexico during the teaching-learning process.

Regeneration and modeling of fixed-bed adsorption of fluoride on bone char

  • Hugo D. Garcia;Rigoberto Tovar;Carlos J. Duran;Virginia Hernandez;Ma. R. Moreno;Ma. A. Perez
    • Advances in environmental research
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    • v.12 no.1
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    • pp.17-40
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    • 2023
  • This article presents studies of the adsorption process in a continuous system of fluoride solutions at a concentration of 30 mg/L using a bone char packed in fixed-bed columns, as well as regeneration studies in the same system using HNO3, HCl and NaOH at 0.01, 0.1 and 1 M. The Thomas Model, Artificial Neural Networks (ANNs), Numerical Integration and Mass Transfer Zone were used for the modeling of asyemmetrical breakthrough curves obtained from the fluoride adsorption on bone char. The maximum adsorption capacity of the breakthrough curves was estimated, and various design parameters of the columns were obtained for the different operating conditions. Results showed that an improvement in the modeling capabilities of the Thomas model can be obtained using ANNs. Moreover, ANNs are useful for determining reasonable and accurate design parameters of packed-bed adsorption columns. This modeling approach can be useful for the process system engineering of dynamic adsorption systems involved in the field of water treatment and purification. It is important to highlight that the obtained results indicate that, when using HCl or HNO3 at a concentration of 0.1 M, a large number of adsorption-desorption cycles are obtained and, therefore, the highest values of adsorption capacity, which leads to a reduction in operation costs.

Risk factors of type 2 diabetes among Korean adults: The 2001 Korean national health and nutrition examination survey

  • Chung, Hae-Rang;Perez-Escamilla, Rafael
    • Nutrition Research and Practice
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    • v.3 no.4
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    • pp.286-294
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    • 2009
  • This study aimed to identify risk factors for type 2 diabetes (T2D) in Korea, a rapidly changing country. Data of 5,132 adults aged 20-85 were used from the 2001 Korean Health and Nutrition Examination Survey. Multiple logistic regression was carried out to identify risk factors for T2D. Three models were specified: (i) socioeconomic and demographic factors (model 1: age, gender, education, poverty income ratio, employment), (ii) behavioral risk factors and covariates (model 2: obesity, physical activity, smoking, alcohol drinking, dietary quality, family history of T2D, co-morbidity) and (iii) socioeconomic, demographic, and behavioral factors (model 3). The prevalence of T2D was 7.4%. Less education (OR 1.41, 95% CI 1.08-1.84), age (OR 2.19, 95% CI 1.56-3.08 in 40-59 yrs, OR 4.05, 95% CI 2.76-5.95 in 60 yrs + comparing to 20-39 yrs) and abdominal obesity (OR 2.24, 95% CI 1.79-2.82) were risk factors for T2D even after controlling for other factors simultaneously. There was a significant association of T2D with ever smoking (OR 1.34, 95% CI 1.06-1.67). The relationship of age with T2D was modified by gender in model 1 and the relationship of smoking with T2D was modified by obesity in model 2. Less educated, older, obese or ever smokers were more likely to have T2D. Gender mediated the relationship of age, and obesity mediated the relationship of smoking, with T2D. Intervention programs for T2D in Korea should take the interactions among risk factors into account.

Temporal and Spatial Distribution of Surface Solar Radiation in Korea Peninsula (한반도에서 지표면 태양광의 시공간 분포)

  • Lee, Kyutae;Jee, Joonbum;Zo, Ilsung;Choi, Youngjin
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.40.1-40.1
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    • 2010
  • 인간의 삶과 밀접한 관련이 있는 태양 에너지는 전세계적으로 에너지 부족 문제 해결방안을 위한 대체 에너지 자원으로 각광 받고 있다. 즉 태양으로부터 방출되어 지표면에 도달하는 태양광은 연간 약 23,000 TW(Perez et al., 2009)로써 다른 어떤 종류의 에너지원보다 풍부하기 때문에 태양광 발전은 양적인 측면에서의 무한한 잠재력뿐만 아니라 환경적인 측면에서 무공해라는 장점을 가진다. 특히 국내에서는 2030년까지 태양광 에너지와 풍력 및 수소에너지들은 3대 국가 에너지 전략 분야로 집중 육성되고 있다(한국과학기술정보연구원, 2007). 지표면에 도달하는 태양 에너지 평가 및 분석을 위하여 일사계에 의한 관측 자료가 이용될 수 있으나 관측 영역 및 관측 정밀도 문제 때문에 태양 복사 모델(Solar Radiative Transfer Model)에 의한 계산 자료가 중요하게 활용된다. 이 연구에서 한반도의 지표면 태양광 계산을 위하여 사용된 모델은 Iqbal(1983)에 근거한 것으로써 단일 기층의 모형대기를 가정한 모델이며 상세 모델(Line-by-Line Model)에 의하여 보정하여 2009년 1월부터 2009년 12월까지 한반도의 지표면 태양광 시공간 분포를 계산하였다. 이 계산을 위하여 대기 중의 가스와 에어로졸 및 구름 성분들에 대한 모델 입력자료 등이 요구되며 이 자료들은 기상청의 수치 모델(Regional Date Assimilation and Prediction System; RDAPS)과 기상 관련 인공위성(OMI와 MODIS 및 MTSAT-1R 등)으로부터 발췌하여 사용하였다. 그 결과 이 연구 기간(2009년 1월 ~ 2009년 12월)동안 1 km 간격의 수평면에 대하여 계산된 한반도의 지표면 태양광은 안동과 대구 및 진주를 연결하는 지역에서 최대값($5400MJ/m^2$ 이상)이 나타났다. 그러나 지표면 일사 관측 자료의 공간 분포는 이 연구 결과와 차이가 있었으며 그 원인은 관측소 일사계의 보정 및 관리운영에 따른 자료 정확성 결여 때문으로 평가된다.

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Differentiation of Beef and Fish Meals in Animal Feeds Using Chemometric Analytic Models

  • Yang, Chun-Chieh;Garrido-Novell, Cristobal;Perez-Marin, Dolores;Guerrero-Ginel, Jose E.;Garrido-Varo, Ana;Cho, Hyunjeong;Kim, Moon S.
    • Journal of Biosystems Engineering
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    • v.40 no.2
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    • pp.153-158
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    • 2015
  • Purpose: The research presented in this paper applied the chemometric analysis to the near-infrared spectral data from line-scanned hyperspectral images of beef and fish meals in animal feeds. The chemometric statistical models were developed to distinguish beef meals from fish ones. Methods: The meal samples of 40 fish meals and 15 beef meals were line-scanned to obtain hyperspectral images. The spectral data were retrieved from each of 3600 pixels in the Region of Interest (ROI) of every sample image. The wavebands spanning 969 nm to 1551 nm (across 176 spectral bands) were selected for chemometric analysis. The partial least squares regression (PLSR) and the principal component analysis (PCA) methods of the chemometric analysis were applied to the model development. The purpose of the models was to correctly classify as many beef pixels as possible while misclassified fish pixels in an acceptable amount. Results: The results showed that the success classification rates were 97.9% for beef samples and 99.4% for fish samples by the PLSR model, and 85.1% for beef samples and 88.2% for fish samples by the PCA model. Conclusion: The chemometric analysis-based PLSR and PCA models for the hyperspectral image analysis could differentiate beef meals from fish ones in animal feeds.

Hisrological Alterations and Immune Response Induced by Pet Toxin During Colonization with Enteroaggregative Escherichia coil (EAEC) in a Mouse Model Infection

  • Eslava, Carlos;Sainz, Teresita;Perez, Julia;Fresan, Ma.Cristina;Flores, Veronica;Jimenez, Luis;Hernandez, Ulises;Herrera, Ismael
    • Journal of Microbiology
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    • v.40 no.2
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    • pp.91-97
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    • 2002
  • Enteroaggregative E. coil (EAEC) is an important aethiological causal agent of diarrhea in people of developed and undeveloped countries. Different in vitro and in vivo models have been proposed to study the pathdgenic and immune mechanisms of EAEC infaction. The aim of this study was to analyze whether BALB/c mice could be used as an animal model to study EAEC pathogenesis Six-week-old BALB/c mice were inoculated with EAEC strain 042 (044:H88) nalidixic acid resistant, and re-inoc-ulated ten days after. Mice feces were monitored for the presence of the EAEC strain over a period of 20 days . Bacteria were enumerated on MacConkey agar containing 100$\mu$g of nalidixic acid per ml. Results showed that 35% of the animals were colonized for 3 days, 15% for 5 and 10% for more than 7 days . After re-inoculation only 16% of the animals remained colonized for more than 3 days. During the necropsy, the intestinal fluid of same of the infected animals presented mucus and blood. Six of these fluids showed the presence of IgA antibodies againset Pet toxin and IgG natibodies raised against the toxin were also detected in the animal serum. Histopathologic evidence confirms the stimulation of mucus hypersecretion, an increased amount of goblet cells and the presence of bacterial aggregates in the apical surfaces of intestinal epithelial cells. Edema was present in the submucosa. These results suggest that BALB/c mice could be used as an animal model for in vivo study of EAEC infection.