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      • A family of heuristics for agent-based elastic Cloud bag-of-tasks concurrent scheduling

        Gutierrez-Garcia, J.O.,Sim, K.M. North-Holland ; Elsevier Science Ltd 2013 Future generation computer systems Vol.29 No.7

        The scheduling and execution of bag-of-tasks applications (BoTs) in Clouds is performed on sets of virtualized Cloud resources that start being exhausted right after their allocation disregarding whether tasks are being executed. In addition, BoTs may be executed in potentially heterogeneous sets of Cloud resources, which may be either previously allocated for a different and fixed number of hours or dynamically reallocated as needed. In this paper, a family of 14 scheduling heuristics for concurrently executing BoTs in Cloud environments is proposed. The Cloud scheduling heuristics are adapted to the resource allocation settings (e.g., 1-hour time slots) of Clouds by focusing on maximizing Cloud resource utilization based on the remaining allocation times of Cloud resources. Cloud scheduling heuristics supported by information about BoT tasks (e.g., task size) and/or Cloud resource performances are proposed. Additionally, scheduling heuristics that require no information of either Cloud resources or tasks are also proposed. The Cloud scheduling heuristics support the dynamic inclusion of new Cloud resources while scheduling and executing a given BoT without rescheduling. Furthermore, an elastic Cloud resource allocation mechanism that autonomously and dynamically reallocates Cloud resources on demand to BoT executions is proposed. Moreover, an agent-based Cloud BoT scheduling approach that supports concurrent and parallel scheduling and execution of BoTs, and concurrent and parallel dynamic selection and composition of Cloud resources (by making use of the well-known contract net protocol) from multiple and distributed Cloud providers is designed and implemented. Empirical results show that BoTs can be (i) efficiently executed by attaining similar (in some cases shorter) makespans to commonly used benchmark heuristics (e.g., Max-min), (ii) effectively executed by achieving a 100% success execution rate even with high BoT execution request rates and executing BoTs in a concurrent and parallel manner, and that (iii) BoTs are economically executed by elastically reallocating Cloud resources on demand.

      • KCI등재

        Research and development on heat pump systems in Mexico using geothermal energy

        Alfonso Garcia-Gutierrez,Rosa M. Barragan-Reyes,Victor M. Arellano-Gomez 한국물리학회 2010 Current Applied Physics Vol.10 No.2

        Extensive research and development work on heat pumps operating on geothermal and waste energy has been carried out by Instituto de Investigaciones Electricas, Mexico. Systems include (i) mechanical compression;(ⅱ) absorption – one- and two-stage and double absorption; (ⅲ) heat transformers, and (ⅳ)hybrid, heat pump systems. Specific work and results are described on three applications: (a) a mechanical compression heat pump commissioned for brine purification and operating on low-pressure geothermal steam in Los Azufres geothermal field; (b) a cooling and refrigeration ammonia/water absorption heat pump operating on low-enthalpy geothermal energy and tested in Los Azufres and Cerro Prieto geothermal fields, and (c) an absorption heat transformer tested extensively to evaluate the performance of ternary solutions as working fluids.

      • KCI등재

        A NOTE ON A WEYL-TYPE ALGEBRA

        ( Juan C. Gutierrez Fernandez ),( Claudia I. Garcia ) 호남수학회 2016 호남수학학술지 Vol.38 No.2

        In a paper of S. H. Choi [2], the author studied the derivations of a restricted Weyl Type non-associative algebra, and determined a 1-dimensional vector space of derivations. We de- scribe all the derivations of this algebra and prove that they form a 3-dimensional Lie algebra.

      • KCI등재

        Optimal Dispatch Model for Demand Response Aggregators

        Victor J. Gutierrez-Martinez,Enrique A. Zamora-Cardenas,Alejandro Pizano-Martinez,Jose M. Lozano-Garcia,Miguel A. Gomez-Martinez 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

        This paper proposes a new three-phase optimal dispatch model for multiple Demand Response (DR) aggregators. By means of the unbalanced distribution system modeling, DR involvement of single- and three-phase consumers is considered avoiding aggravating the asymmetric balancing between phases, as opposed to traditional positive-sequence DR approaches. Furthermore, this proposal can consider several DR service providers by means of the explicit inclusion of their characteristics, in the form of cost functions and capacity, in an optimal dispatch model for DR support at the distribution system level. Hence, this proposal helps to eliminate any possible uncertainty about the provision of DR services by improving the traditional hierarchical scheme adopted based on prices issued by the Independent System Operator (ISO). The model is implemented and solved combining the two state-of-the-art computational tools, Matlab® and OpenDSS. The former is used to solve the optimization problem, whereas the latter is used to perform numerical simulations of three-phase unbalanced power flow; both tools allow a straightforward model implementation resulting in a tool easily modified and updated. The effectiveness of the proposed approach is numerically demonstrated using the IEEE 13- and 123-node test feeders, in which undesirable operating scenarios are corrected by the implementation of the optimal dispatch of DR resources in very short computational times. Based on the results, it is shown how the ISO is capable to request DR considering several aggregators competing at the distribution system level. Finally, the loss reduction has been included in the objective function, showing that the proposal optimally dispatches the DR aggregators to conveniently minimize the ISO’s operational costs.

      • KCI등재

        A NOTE ON A WEYL-TYPE ALGEBRA

        Fernandez, Juan C. Gutierrez,Garcia, Claudia I. The Honam Mathematical Society 2016 호남수학학술지 Vol.38 No.2

        In a paper of S. H. Choi [2], the author studied the derivations of a restricted Weyl Type non-associative algebra, and determined a 1-dimensional vector space of derivations. We describe all the derivations of this algebra and prove that they form a 3-dimensional Lie algebra.

      • KCI등재

        Performance of ChatGPT, Bard, Claude, and Bing on the Peruvian National Licensing Medical Examination: a cross-sectional study

        Betzy Clariza Torres-Zegarra,Wagner Rios-Garcia,Alvaro Micael Ñaña-Cordova,Karen Fatima Arteaga-Cisneros,Xiomara Cristina Benavente Chalco,Marina Atena Bustamante Ordoñez,Carlos Jesus Gutierrez Rios,C 한국보건의료인국가시험원 2023 보건의료교육평가 Vol.20 No.-

        Purpose We aimed to describe the performance and evaluate the educational value of justifications provided by artificial intelligence chatbots, including GPT-3.5, GPT-4, Bard, Claude, and Bing, on the Peruvian National Medical Licensing Examination (P-NLME). Methods This was a cross-sectional analytical study. On July 25, 2023, each multiple-choice question (MCQ) from the P-NLME was entered into each chatbot (GPT-3, GPT-4, Bing, Bard, and Claude) 3 times. Then, 4 medical educators categorized the MCQs in terms of medical area, item type, and whether the MCQ required Peru-specific knowledge. They assessed the educational value of the justifications from the 2 top performers (GPT-4 and Bing). Results GPT-4 scored 86.7% and Bing scored 82.2%, followed by Bard and Claude, and the historical performance of Peruvian examinees was 55%. Among the factors associated with correct answers, only MCQs that required Peru-specific knowledge had lower odds (odds ratio, 0.23; 95% confidence interval, 0.09–0.61), whereas the remaining factors showed no associations. In assessing the educational value of justifications provided by GPT-4 and Bing, neither showed any significant differences in certainty, usefulness, or potential use in the classroom. Conclusion Among chatbots, GPT-4 and Bing were the top performers, with Bing performing better at Peru-specific MCQs. Moreover, the educational value of justifications provided by the GPT-4 and Bing could be deemed appropriate. However, it is essential to start addressing the educational value of these chatbots, rather than merely their performance on examinations.

      • Human Papillomavirus Genotypes among Females in Mexico: a Study from the Mexican Institute for Social Security

        Salcedo, Mauricio,Pina-Sanchez, Patricia,Vallejo-Ruiz, Veronica,Monroy-Garcia, Alberto,Aguilar-Lemarroy, Adriana,Cortes-Gutierrez, Elva I.,Santos-Lopez, Gerardo,Montoya-Fuentes, Hector,Grijalva, Renan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

        Background: The aetiological relationship between human papillomavirus (HPV) infection and cervical cancer (CC) is widely accepted. Our goal was to determine the prevalence of HPV types in Mexican women attending at the Mexican Institute for Social Security from different areas of Mexico. Materials and Methods: DNAs from 2,956 cervical samples were subjected to HPV genotyping: 1,020 samples with normal cytology, 931 with low-grade squamous intraepithelial lesions (LGSIL), 481 with high grade HGSIL and 524 CC. Results: Overall HPV prevalence was 67.1%. A total of 40 HPV types were found; HPV16 was detected in 39.4% of the HPV-positive samples followed by HPV18 at 7.5%, HPV31 at 7.1%, HPV59 at 4.9%, and HPV58 at 3.2%. HPV16 presented the highest prevalence both in women with altered or normal cytology and HPV 18 presented a minor prevalence as reported worldwide. The prevalence ratio (PR) was calculated for the HPV types. The analysis of PR showed that HPV16 presents the highest association with CC, HPV 31, -33, -45, -52 and -58 also demonstrating a high association. Conclusions: The most prevalent HPV types in cervical cancer samples were -16, -18, -31, but it is important to note that we obtained a minor prevalence of HPV18 as reported worldwide, and that HPV58 and -52 also were genotypes with an important prevalence in CC samples. Determination of HPV genotypes is very important in order to evaluate the impact of vaccine introduction and future cervical cancer prevention strategies.

      • One-dimensional ordered growth of magneto-crystalline and biocompatible cobalt ferrite nano-needles

        Ravichandran, M.,Oza, G.,Velumani, S.,Ramirez, J.T.,Garcia-Sierra, F.,Andrade, N.B.,Garza-Navarro, M.A.,Garcia-Gutierrez, D.I.,Asomoza, R. North-Holland 2014 Materials letters Vol.135 No.-

        <P>In this letter, we have reported a novel synthesis of CoFe2O4 nano-needles by a co-precipitation method using precursors of ferric chloride and cobalt nitrate at 80 degrees C. The structural and magnetic properties of as-grown needle-like CoFe2O4 nanostructures exhibit cubic spinel structure. CoFe2O4 nano-needles have an average diameter of 15 nm with an aspect ratio of 30:50, which was depicted by High-resolution transmission electron microscopy (HRTEM). Superconducting Quantum Interference Device (SQUID) confirmed the property of superparamagnetism. The magnetic measurement illustrated that the coercivity (Hc) of CoFe2O4 nano-needles increased from -145.84 Oe at 5 K to -25.38 Oe at 312 K. The cell viability studies of CoFe2O4 nano-needles were performed in the concentration range of 5-1000 mu g/ml on L6 (Skeletal muscle cell lines) and Hep-2 (Larynx carcinoma) cells using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was more than 50% cell viability for both the cell lines, but Hep-2 cells were more prone to killing as compared to L6 cells. Such biocompatible nanostructures can be used as drug-delivery systems for cancer therapeutics. (C) 2014 Elsevier B.V. All rights reserved.</P>

      • KCI등재

        Minimally Invasive versus Open Surgery for Spinal Metastasis: A Systematic Review and Meta-Analysis

        Hinojosa-Gonzalez David Eugenio,Roblesgil-Medrano Andres,Villarreal-Espinosa Juan Bernardo,Tellez-Garcia Eduardo,Bueno-Gutierrez Luis Carlos,Rodriguez-Barreda Jose Ramon,Flores-Villalba Eduardo,Martin 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.4

        Bones are the third most common location for solid tumor metastasis affecting up to 10% of patients with solid tumors. When the spine is involved, thoracic and lumbar vertebrae are frequently affected. Access to spinal lesions can be through minimally invasive surgery (MIS) or traditional open surgery (OS). This study aims to determine which method provides an advantage. Following the PRISMA (Preferred Inventory for Systematic Reviews and Meta-Analysis) guidelines, a systematic review was conducted to identify studies that compare MIS with OS in patients with spinal metastatic disease. Data were analyzed using Review Manager ver. 5.3 (RevMan; Cochrane, London, UK). Ten studies were included. Operative time was similar among groups at -35.23 minutes (95% confidence interval [CI], -73.36 to 2.91 minutes; <i>p</i>=0.07). Intraoperative bleeding was lower in MIS at -562.59 mL (95% CI, -776.97 to -348.20 mL; <i>p</i><0.00001). OS procedures had higher odds of requiring blood transfusions at 0.26 (95% CI, 0.15 to 0.45; <i>p</i><0.00001). Both approaches instrumented similar numbers of levels at -0.05 levels (95% CI, -0.75 to 0.66 levels; <i>p</i>=0.89). We observed a decreased need for postoperative bed rest at -1.60 days (95% CI, -2.46 to -0.74 days; <i>p</i>=0.0003), a shorter length of stay at -3.08 days (95% CI, -4.50 to -1.66 days; <i>p</i>=0.001), and decreased odds of complications at 0.60 (95% CI, 0.37 to 0.96; <i>p</i>=0.03) in the MIS group. Both approaches revealed similar reintervention rates at 0.65 (95% CI, 0.15 to 2.84; <i>p</i>=0.57), effective rates of reducing metastasis-related pain at -0.74 (95% CI, -2.41 to 0.94; <i>p</i>=0.39), and comparable scores of the Tokuhashi scale at -0.52 (95% CI, -2.08 to 1.05; <i>p</i>=0.41), Frankel scale at 1.00 (95% CI, 0.60 to 1.68; <i>p</i>=1.0), and American Spinal Injury Association Scale at 0.53 (95% CI, 0.21 to 1.37; <i>p</i>=0.19). MIS appears to provide advantages over OS. Larger and prospective studies should fully detail the role of MIS as a treatment for spine metastasis.

      • KCI등재후보

        Perinatal/Postnatal Study of D-003, a Mixture of Long-Chain Fatty Acids, in Rats

        M.D. Rodriguez,J.E. Gonzalez,E.F. Leon,A. Gutierrez,G. Marrero,R. Gamez,H Garcia,,E Goicochea,Y. Rodriguez,A. Gomez 한국식품영양과학회 2006 Journal of medicinal food Vol.9 No.2

        D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax with cholesterol-low-ering and antiplatelet effects. In order to further characterize the developmental toxicity during the treatment period from lategestation up to weaning of the offspring, pregnant females received 0 (control), 500, and 1,000 mg/kg/day D-003 daily byoral gavage beginning at day 15 of pregnancy and through gestation until day 21 postpartum. Maternal clinical signs, bodyweight, and food intake were measured at regular intervals during gestation and lactation. Live pups were weighed, sexed,and examined for developmental signs. One female and male of each litter were randomly selected to evaluate the reproduc-tive potential. There were no spontaneous or dose-related maternal deaths during the course of this study. The general healthand behavioral condition of offspring was good in all groups. No significant differences among groups were found in com-parisons of litter size, survival through the weaning period, sex ratio, and male and female weights. This peri- and postnatalstudy conducted with D-003 in rats indicated that treatment of the dam during late gestation and lactation did not show ad-versely effects on reproductive performance or fetal development over two generations.

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