Papers by Roberto Rodriguez
The aim of this work is the evaluation of both adsorption-desorption mechanisms of hexavalent chr... more The aim of this work is the evaluation of both adsorption-desorption mechanisms of hexavalent chromium in two metallurgical wastes. These processes were investigated using batch tests. Theses wastes correspond to the metallurgical processes of Ni-Co recovery in Cuban industries. The first one (called SAL-waste) is originated by sulphuric acid leaching and the second one (ACL-waste) is the by-product of ammonia-carbonate metallurgical leaching. The wastes are mainly constituted by iron minerals. Grain size distribution is poorly graded with a average value of diameter is about 0.02 mm. The adsorption isotherms of Cr in ACL and SAL are strongly non-linear and well described by the Freundlich equations (S = Kf Cn w). Desorption isotherms of Cr in both wastes are near-linear and illustrate very well the presence of a hysteretic process. The time of Cr adsorption short and desorption is very fasten. According these results the adsorption of chromate under acid conditions can be attribute...
Office Visual Display Terminal (VDT) work is a paradigmatic case of a work system in which the ad... more Office Visual Display Terminal (VDT) work is a paradigmatic case of a work system in which the adoption of a new technology introduces new associated risks of different natures: visual, musculoskeletal and cognitive. We carried out a Post Occupancy Evaluation at University of Mendoza administrative offices, and made a diagnosis of visual, cognitive and postural risks associated with VDT office work. Our results showed levels of horizontal illuminance lower than the legally required by our legislation, whose regulations need to be revised and updated. We found that 32% of our participants were outside the acceptable range of mental workload. Also, we explored the hypothetical role of glare sources as environmental distractors, finding a statistically significant linear correlation between vertical illuminance level and Stroop interference. This exploratory study described the behavior of many variables of interest in actual work situations, allowing us to propose a general model of V...
In regions with arid climate and many clear-sky days it is very advantageous to illuminate the in... more In regions with arid climate and many clear-sky days it is very advantageous to illuminate the interior spaces with daylight, achieving energy savings and benefits for users. It is therefore necessary an adequate analysis and sunlight control. A total of 15 offices with sunspots over the work space were evaluated. These offices were evaluated through objective and subjective metrics developed to assess daylight spaces: level of illuminance, luminance ratios, risk of glare, uniformity, among others, taking as reference values subjective data. The results showed that of the 8 metric evaluated, only four showed moderate correlations r> 0,5 with users perception. Vertical illuminance at eye, luminance analysis in the near field of view and uniformity values were a more descriptive tool in daylight scenes used together. In this way, this study suggests that it is suitable the use of more than one metric in daylight scenes, deepening in the HDR-image analysis, whose diagnostic power is...
Fil: Rodriguez, Roberto German. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centr... more Fil: Rodriguez, Roberto German. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina
The Computer Journal, 2017
Various constraints of Static Random Access Memory (SRAM) are leading to consider new memory tech... more Various constraints of Static Random Access Memory (SRAM) are leading to consider new memory technologies as candidates for building on-chip shared last-level caches (SLLCs). Spin-Transfer Torque RAM (STT-RAM) is currently postulated as the prime contender due to its better energy efficiency, smaller die footprint and higher scalability. However, STT-RAM also exhibits some drawbacks, like slow and energy-hungry write operations, that need to be mitigated before it can be used in SLLCs for the next generation of computers. In this work we address these shortcomings by leveraging a new management mechanism for STT-RAM SLLCs. This approach is based on the previous observation that although the stream of references arriving at the SLLC of a Chip MultiProcessor (CMP) exhibits limited temporal locality, it does exhibit reuse locality, i.e., those blocks referenced several times manifest high probability of forthcoming reuse. As such, conventional STT-RAM SLLC management mechanisms, mainly focused on exploiting temporal locality, result in low efficient behavior. In this paper, we employ a cache management mechanism that selects the contents of the SLLC aimed to exploit reuse locality instead of temporal locality. Specifically, our proposal consists in the inclusion of a Reuse Detector between private cache levels and the STT-RAM SLLC. Its mission is to detect blocks that do not exhibit reuse, in order to avoid their insertion in the SLLC, hence reducing the number of write operations and the energy consumption in the STT-RAM. Our evaluation, using multiprogrammed workloads in quad-core, eight-core and 16-core systems, reveals that our scheme reports on average, energy reductions in the SLLC in the range of 37-30%, additional energy savings in the main memory in the range of 6-8% and performance improvements of 3% (quad-core), 7% (eight-core) and 14% (16-core) compared to an STT-RAM SLLC baseline where no reuse detector is employed. More importantly, our approach outperforms DASCA, the state-of-the-art STT-RAM SLLC management, reporting -depending on the specific scenario and the kind of applications used-SLLC energy savings in the range of 4-11% higher than those of DASCA, delivering higher performance in the range of 1.5-14%, and additional improvements in DRAM energy consumption in the range of 2-9% higher than DASCA.
LEUKOS, 2012
ABSTRACT Glare is a common visual stressor of office work and in today’s offices the prevalence o... more ABSTRACT Glare is a common visual stressor of office work and in today’s offices the prevalence of information and communication technologies adds additional mental demands. The aim of this study was to explore the role of light as a cognitive stressor in visual display terminal (VDT) work. We used a large area light source in a 2x2x2 full factorial experimental design. We assessed cognitive efficiency using the RTLX method and cognitive effectiveness using the RST method in different lighting scenarios. The main effects analysis showed lower working memory capacity for high luminance and large source, with statistically significant lower cognitive performance in prosaccade conditions. No statistically significant relationship was found between cognitive efficiency and the experimental factors.
Journal of Quality Technology, 1987
A computationally convenient expression is found for the average outgoing quality (AOQ) in the si... more A computationally convenient expression is found for the average outgoing quality (AOQ) in the situation where a product is subjected to multiple 100% inspections, each item possesses several characteristics that are to be inspected, the two types of inspection errors depend on the particular characteristic but not on the inspector, and an item is classified as nonconforming if any of its characteristics are classified as nonconforming. Programs in FORTRAN and in BASIC that perform the necessary computations are provided. It is also shown that the logarithm of the AOQ after n inspections is a linear function of n, and the rate of decrease depends only on the two types of errors associated with classifying an item as conforming or nonconforming.
Revista Tecnica De La Facultad De Ingenieria Universidad Del Zulia, 2019
Esta publicación científica en formato digital es continuidad de la revista impresa
Archivos argentinos de pediatria, 2016
Achieving adequate lighting in neonatal intensive care units is a major challenge: in addition to... more Achieving adequate lighting in neonatal intensive care units is a major challenge: in addition to the usual considerations of visual performance, cost, energy and aesthetics, there appear different biological needs of patients, health care providers and family members. Communicational aspects of light, its role as a facilitator of the visual function of doctors and nurses, and its effects on the newborn infant physiology and development were addressed in order to review the effects of light (natural and artificial) within neonatal care with a focus on development. The role of light in regulating the newborn infant circadian cycle in particular and the therapeutic use of light in general were also reviewed. For each aspect, practical recommendations were specified for a proper well-lit environment in neonatal intensive care units.
Computación y Sistemas, Dec 31, 2006
Image segmentation plays an important role in many systems of computer vision. According to crite... more Image segmentation plays an important role in many systems of computer vision. According to criterions of many authors the segmentation finishes when it satisfies the goals of the observer. For that reason, an only method there is not able of solving all the problems that exists in the present time. In this work, we carry out a comparison between two segmentation techniques; namely, through the mean shift, where we give a new algorithm, and by using spectral methods. In the paper we discuss, through examples with biomedical real images, the advantages and disadvantages of them.
INTRODUCCION Los productores de la empresa Unificacion Nueva Laguna S. de S. S., ubicada en el Ej... more INTRODUCCION Los productores de la empresa Unificacion Nueva Laguna S. de S. S., ubicada en el Ejido Lazaro Cardenas, Municipio de San Pedro, Coahuila, son agricultores del medio rural con giro netamente agricola, dedicados a la produccion del cultivo del algodonero, poseen amplia experiencia en los aspectos de produccion, administracion y comercializacion y tienen 20 anos constituidos como Sociedad de Solidaridad Social. Cabe hacer mencion que una S de S S, es una forma juridica de organizacion mediante la cooperacion de los socios para llevar a cabo fines especificos como la creacion de fuentes de trabajo, conservacion y mejoramiento del medio ambiente, explotacion de los recursos naturales, la produccion, industrializacion y comercializacion de bienes y servicios asi como la educacion a los socios y su familia. Para ser socio se requiere ser persona fisica, de nacionalidad mexicana, en especial ejidatario. Y pueden realizar actividades mercantiles.
Rev Cuba Estomatol, Dec 1, 1996
Abstract : This thesis redeveloped the Network Operating System (NETOS) software, which is patter... more Abstract : This thesis redeveloped the Network Operating System (NETOS) software, which is patterned after the OSI 7-Layer Model and runs on a Local Area Network at the Air Force Institute of Technology, from the programming language C to the programming language Ada, with modifications to support variable length messages. The approach taken used a software development methodology which contains the following phases; requirements analysis, design, implementation, and testing. The requirement analysis phase consisted of an enumerated listing of the requirement specifications supported by SADT diagrams. The design phase transformed these diagrams to a structural chart representation of the design. Implementation of the software was written in Janus/Ada for the work stations and Whitesmith C for the central system. Testing was an integral part of the implementation phase and was accomplished at each level of the 7-Layer model.
Environmental Earth Sciences, 2016
Mining wastes often contain high concentrations of toxic elements, whose mobility and dispersion ... more Mining wastes often contain high concentrations of toxic elements, whose mobility and dispersion may pose an environmental hazard for soils, water, ecosystems and people. This article describes the partial application of a methodology designed to evaluate the pollution potential of abandoned mining wastes, using two indices for potential pollution evaluation: an index of contamination (IC) and a hazard average quotient (CPP). Composite samples, consisting of at least 30 subsamples, were taken at three sulfidic tailings impoundments in the mining area of Mazarrón (SE Spain). Mineralogical, physical, and chemical characteristics were analyzed: color, particle size, powder XRD analysis, pH, total content of toxic elements, and concentrations in leachates by the standard procedure EN-12457-2. Tailings were extremely acid (pH 2.30-2.52). Some ranges of total content (in mg/kg) were: As (381-565), Pb (2602-4487), Sb (139-170), and Zn (3254-5652). The concentration measured in the EN-12457 leachates (lg/L) was as high as 367,000 for Zn, 2030 for Cu, and 974 for Cd. The IC and CPP values were among the most high of the tailings inventoried in Spain. The combination of the indices provided a good estimation of the potential toxicity of these wastes, and it can be useful to rank abandoned mining waste facilities.
Cuadernos De Psicomotricidad, 2013
Uploads
Papers by Roberto Rodriguez