bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementación en FPGA de un módulo lineal de estimación de parámetros eléctricos para un sistema fotovoltaico (PVS)
Authors: Lozano-Rivera Clevis , Oviedo Marco , Chacón-Rodríguez Alfonso , Meza Carlos 
Published: February 2020

Este artículo presenta el análisis y evaluación de la implementación FPGA de un modelo adaptativo lineal para la estimación de parámetros eléctricos linealizados. Estos parámetros pueden provenir, por ejemplo, de modelos no lineales requeridos para el monitoreo de la eficiencia o el control de lazo cerrado de sistemas complejos, con necesidades de velocidad de procesamiento no alcanzables por sistemas embebidos tradicionales (en el orden de una mega muestra por segundo o más). El modelo implementado se compone de un juego de ecuaciones que se han derivado de una aproximación basada en el solucionador numérico típico de Euler para ecuaciones diferenciales. En el caso acá presentado, los parámetros representan el comportamiento dinámico de un panel generador fotovoltaico. El objetivo del modelo es evaluar el desempeño de algoritmos distribuidos de búsqueda del punto de máxima potencia, a partir de una única ecuación que describe su relación voltaje-corriente. El algoritmo se evalúa primero usando una descripción Verilog a nivel de transferencia de registros (RTL), y luego se prueba sobre una FPGA comercial, con datos generados desde un modelo dorado de alto nivel. La validación final sobre herramientas automatizadas de diseño electrónico de circuitos integrados (EDA) muestran que el diseño no es solo viable para portarse a una tecnología CMOS comercial, sino que es eficiente en términos de velocidad de procesamiento y consumo de potencia. Dicha eficiencia lo hace adecuado para el monitoreo y control de paneles solares interconectados.
El concepto frontera en la geografía humana
Authors: Arriaga Rodríguez Juan Carlos 
Published: February 2020

En las ciencias sociales, el concepto frontera tiene diferentes significados y usos explicativos en lo temporal y lo espacial. En cada época histórica y lugar del planeta, el concepto y sus palabras equivalentes tienen funciones políticas, económicas, militares y sociales diferentes. El siguiente texto es un artículo de revisión en el que se explica que las diferentes definiciones del concepto frontera en la geografía humana fueron construidas a lo largo del siglo XX con base en determinadas categorías geográficas, fenómenos y procesos sociales, y en los sujetos involucrados en tales procesos. Se explican las dos posturas dominantes en torno al concepto frontera dentro de la geografía humana: la “frontera como espacio absoluto” y la “frontera como espacio socialmente construido”. Se analizan las tesis elaboradas en el marco de esas posturas, y se mencionan aquellas que han tenido una influencia directa en el estudio de las fronteras en América Latina.
Un viaje por la movilidad cotidiana. El espacio entre el transporte y el individuo
Authors: Salerno Bruno 
Published: February 2020

Este artículo construye un recorrido a lo largo de la producción actual dela movilidad cotidiana poniendo atención en el problema de la oferta y la demanda. En este sentido, se expone un avance progresivo desde enfoques más centrados en el transporte, hasta enfoques más orientados hacia el individuo. Este problema va de la mano de la tensión entre agregadoindividuo. Finalmente, la argumentación va a ser construida en clave de la relación entre la movilidad como una práctica social y las relaciones sociales y la producción del espacio en general. Las conclusiones versan, en gran medida, sobre las implicancias y supuestos de la adopción del individuo como objeto de estudio.
Cost Effective Analysis Between Glimipiride and Gliptin Used in Diabetic Patients in Tertiary Care Hospital
Authors: Bharathi DR  , Abubaker Siddiq  , Ancy Jose George  
Published: February 2020

Diabetes mellitus is a spectrum of common metabolic disorders arising from various mechanisms all resulting in hyperglycemia. It is a disorder which can lead to coronary artery disease, cerebro- vascular disease, Nephropathy, Diabetic retinopathy, Neuropathy. So, early treatment is necessary to prevent these complications. In this regard, Oral Hypoglycemic drugs are most common type of treatment given for patient. A better cost effective drug can minimize the economic burden on the patients as it is a chronic diseases. The present study was aimed to asses cost effectiveness between glimepride and gliptin that may improve the clinical and economical aspect of patient and increase quality of health in patient. The present study was made to conduct cost effective analysis between glimepride and gliptin. It is a prospective observational study conducted in Basaveshwara Medical College, Hospital and Research Centre and Chitradurga Diabetic Centre for a period of six months. Patients admitted in General medicine above the age of 30 yrs are included. The data was collected from medical records of the patients and documented in suitable designed form.A total of 104 patients were enrolled during the study period, 70 are inpatients and 34 are outpatients. 5 were dropped out from the study. The results reveal that Glimepride has got more efficacy than gliptin. It provided long term Glycemic control than gliptin and also remain less costly compare to gliptin. The one sample student T-test results showed the P value was 0.000*. After follow up glimepride proved to be cost effective drug. Increased health expenditures have led to the need to find out the optimal therapy at the lowest price. This study concluded that Glimepride is more efficacious and cost effective drug than Gliptin. Since diabetes is a chronic disease with long duration, Glimepride might be preferred to Gliptin. It also reveal that glimepride leads to improvements in quality adjusted-life expectancy and is a cost-effective option for the treatment of Type 2 diabetes.
THE INFLUENCE OF ASSESSMENT, SELF-EFICATION THROUGH STUDENT LEARNING OUTCOMES IN INDONESIAN LANGUAGE
Authors: Ijudin  
Published: February 2020

Abstract
This study aimed to learn the results of Indonesian subject which used peer assessment and teacher assessment by the techniques of oral presentations at high school students on the level of different self-efficacy students. The sample was taken were 40 respondents. The data was collected by using an experimental method. Samples were obtained by using stratified random method or multistage random method. The design of treatment which was used was the analysis design treatment by level 2 x 2. The results were found that 1). The test results proved that the average of learning outcomes of Indonesian subject in a group of students who were given ratings by peers had significantly different results compared to the average of learning outcomes of Indonesian subject assessment who were given by the teacher.
La Universidad en la Escuela: Proyecto de Colaboración con la Red de Centros Comunidades de Aprendizaje
Authors: Segovia Aguilar Blas , García Cabrera María del Mar 
Published: February 2020

En esta aportación describimos el proyecto de innovación docente “La universidad en la escuela: Proyecto de colaboración con la Red de Centros Comunidades de Aprendizaje”, realizado durante el curso 2017/2018 cuya finalidad principal es fortalecer líneas de cooperación entre las escuelas de Comunidades de Aprendizaje de la provincia de Córdoba y la Facultad de Ciencias de la Educación de la Universidad de Córdoba.Las actividades desarrolladas han implicado a profesores y estudiantes universitarios que realizan voluntariado en estos centros educativos y a docentes de los mismos, organizándose en dos escenarios: en las escuelas, participando en la aplicación de las Actuaciones de Éxito Educativo y en la Facultad, con la puesta en marcha de un Seminario de Tertulias Pedagógicas Dialógicas para la discusión teórico práctica de las bases científicas en las que se sustentan dichas Actuaciones.Los resultados se presentan en relación a los objetivos planteados, destacando la progresiva vinculación del proyecto de Comunidades de Aprendizaje con la formación inicial del profesorado y la formación permanente de los docentes. Esto es valorado como una fortaleza que permite prolongar la dinámica de trabajo en los próximos cursos para consolidar las necesarias relaciones entre Escuela-Universidad a través de redes de cooperación mutua.
What is the Future Demand for Petroleum Engineers?
Authors: Rassenfoss Stephen 
Published: February 2020

At the end of a presentation on BP’s annual energy outlook last year, a petroleum engineering student from Greece asked, “Is a job as a petroleum engineer a good idea for the next decade?”
Then BP CEO Bob Dudley responded by saying, “A job or training as an engineer of any kind is so important. There is going to be a huge need for that as you can see from Spencer’s outlook.”
He was referring to the presentation made by Spencer Dale, group chief economist for BP, whose outlook showed oil demand likely growing until 2030, and remaining around 100 million B/D through 2050 while natural gas demand continues to rise.
But how many oilfield engineers will be working in the decades ahead? A short JPT online story about that question struck a nerve with readers. It was one of the most-read stories online over the past year, with 21,000 views.
The most downloaded SPE paper in 2019 on OnePetro was “The End of Petroleum Engineering as We Know It,” which predicted a significant change in what engineers do and the number needed to do it over the long term (SPE 194746). The idea for the paper came when 2016 SPE President Nathan Meehan said he began to have doubts about whether the assurances he was offering when asked that question by students were a realistic appraisal of the future.
While he is happy to report that his son and a son-in-law both work in the oil business, he was not sure what he would tell his grandchildren.
Exploration and production has always been a business where the risks and the rewards are high, including the danger of layoffs during a downturn. The paper Meehan authored considers how society’s long-term transition to lower-emission energy sources could affect the careers of petroleum engineers. It analyzes what is expected to be a slow-to no-growth industry where digital technology, such as artificial intelligence (AI), will enable fewer engineers to do a lot more.
“It is likely that AI-based products and services will greatly leverage petroleum engineers, enabling one engineer to do the work previously requiring many,” the paper said. It added that the changes “suggest that engineering jobs in the future are likely to be smaller in number and radically different from today.”
The tone of the paper is sobering, but Meehan said what is ending is not petroleum engineering jobs, just long-standing expectations about working in the industry. He said he met many young engineers during his travels as president who should be able to manage the coming changes.
“They are digitally savvy, energetic, and concerned about sustainability issues and ways to lower the carbon intensity of oil and gas production,” he said.
Machine-Learning-Based Early-Warning System Maintains Stable Production
Authors: Feder Judy 
Published: February 2020

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 197365, “A Novel Early Warning System of Oil Production Based on Machine Learning,” by Kang Ma, Hanqiao Jiang, and Junjian Li, China University of Petroleum-Beijing, et al., prepared for the 2019 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 11–14 November. The paper has not been peer reviewed.
After long-term waterflooding, a number of mature oil fields in China have entered the high-water-cut stage, and abnormal production decline has become the primary problem for stable production. This paper describes an accurate, three-step, machine-learning-based early warning system (EWS) that has been used to monitor production and guide strategy in the Shengli field. Adding artificial samples to the training process improved the system’s prediction accuracy greatly (Fig. 1).
Introduction
For conventional Chinese oil fields that have entered the high-water-cut stage after decades of waterflooding, stabilizing production has become increasingly difficult. After stimulation treatments throughout the field’s history, abnormal decline rates—that is, exceeding 5%—occurred more frequently. Production declined dramatically in 2004 and has not been maintained since then.
To prevent future abnormal production declines, an effective EWS was needed that could release a production alarm to enable engineers to take preventive measures in advance. The complete paper includes a discussion of various early-warning models and their limitations.
The paper discusses an EWS based on a neural network method using a previously established data set. Factors that can affect the abnormal decline were selected. The index sets of production composition and injected and produced water obtained from practical statistics were considered as the main assessment indicators. Grey relational analysis was used to evaluate the importance of the different indicators and to eliminate redundant parameters.
Machine learning was adopted to build the EWS. Using the degree of deviation from normal as the input data for the prediction model provided the highest accuracy. However, the basic machine-learning model contains many input parameters that cannot be obtained easily. The number of input parameters was optimized on the basis of the variation of accuracy under different input parameter numbers. To improve prediction accuracy, artificial samples were added to the training process.
The prediction accuracy of the final optimization model can reach 92%. The result reveals the possibility of the occurrence of anomalous decline in different reservoirs, which can guide oilfield production strategy effectively. The EWS was verified by oilfield production.
Fundamentals of Neural-Network Classification
Neural networks use existing data to determine the implicit model between input and output data. Classification and prediction are the most common applications. Neural networks are used in the industry to solve classification and regression problems.
Economic Factors in the Expanding LP-Gas Industry
Authors: Barnes Winthrop M. 
Published: February 2020

Gas Technology Symposium, 17–18 April, Shreveport, Louisiana

Introduction
This study is directed toward examination of the techno-economic problems associated with the natural gas liquids industry. It aims at collection and analysis of the broad technical and economic data vital for a clear understanding of the opportunities available to/and the problems confronting the industry. Consideration is given to the LP-Gas and natural gasoline industries.
In considering the LP-Gas industry, attention is given to:the nature of demand for LP-Gas [for domestic and commercial applications, internal combustion engines, chemicals and synthetic rubber];the availability of supply and required incentives for increased supply;the importance of efficient transportation and storage to permit effective balance of supply and demand; andan over-all picture of industry action required to achieve the maximum potential. An analysis is made of the natural gasoline situation and of future engine and fuel developments which will influence it.
This study does not attempt to answer fully all of the industry problems. It does attempt to define the problems in their proper perspective, to supply some of the basic data required to study them, and to suggest possible avenues of approach. Its aim is to stimulate the individual and collective industry thinking and action required to achieve early maturity.

Domestic and Commercial Market for LP Gas
There are strong indications that the competitive position of LP-Gas as a domestic fuel is not as strong as it must be if this market is to continue to represent 50 per cent of the total for LP-Gas.
LP-Gas must compete with electricity and oil for the domestic and commercial markets. Frequently, appliance purchases are made on the basis of one fuel for cooking, another for water heating, and possibly a third for home heating; the public has not become particularly single utility conscious. The electric industry is invariably a fairly large, well-staffed organization, with funds available for well-planned advertising and sales promotion efforts, and has gone far to promote the domestic and commercial market for its product. On the other hand, the LP-Gas sales, particularly in rural areas, are frequently handled by small dealers who do not have the abilities and backing of the large utility.
Predicting Reservoir Performance by Applying an Unsteady State Solution
Authors: Layton D.D. 
Published: February 2020

Gas Technology Symposium, 17–18 April, Shreveport, Louisiana

Abstract
It is often desirable to predict gas well performance during a relatively short period after opening the well. The conventional methods will become unreliable in the cases of tight or altered formations. This paper explains the mechanics of one of several solutions of performance predictions under unsteady state conditions. The solution, devised by Katz and Cornell, centers around a graphical presentation of the pressure disturbances in a reservoir created by constant flow rates. The variables in the graphical presentation are dimensionless and can be applied to a variety of problems. The procedures in the solution of two problems determining reservoir limits and predicting maximum injection pressure are discussed here, including numericalexamples.

Introduction
The reservoir engineer is called upon to predict different aspects of performance of a gas well with time. Often new completions are involved with no production histories. The engineer then relies on core analyses, and backpressure or production tests using Darcy's law or the back pressure equation. This becomes unreliable when the formation has a low permeability or if it is sufficiently altered from its original state. In these cases performance prediction by applying solutions of the unsteady state equation are useful as well as in other situations where prediction of pressure change with time are needed.

Unsteady State
When a gas reservoir is in an unsteady state, it can be considered as unstable. The flowing pressure with a constant rate is continually changing with time. For practical purposes, the well becomes stabilized when gas in place at its ultimate drainage radius begins moving toward the well bore. After this time further pressure decline under constant rate is caused by depletion. In tight formations pressure change with distance from the well bore is rapid. Draw-down at the well bore is large, while a few feet away, the reservoir will be in an undisturbed condition. This results in steep pressure sinks, which move slowly toward the ultimate drainage radius. During this time, in which a pressure disturbance is being created outward from the wellbore to the ultimate drainage radius, the well is unstabilized and is regarded as being in a condition of unsteady state.
Applications of Recent Reservoir and Petrophysical Developments to a Field Study
Authors: Bethel F.T. , Welbourn M.E. 
Published: February 2020

Fifth Annual Joint Meeting of the Rocky Mountain Petroleum Sections of AIME, 2–3 April, Casper, Wyoming

Abstract
A reservoir and petrophysical study was made of the Red River (Ordovician)reservoir of the Gas City field. The heterogeneous carbonates which make up the reservoir were grouped by the physical properties which control fluid saturations and fluid flow. The fluid content of the reservoir was determined from the capillary characteristics of the groups of rocks and from porosities calculated from the radioactivity log. It was found that the reservoir void volume contains a large percentage of fine pores and a high average water saturation; however, distribution of the larger pores was such that all ranges of porosity will contribute some oil to production.
The utilization of an electronic computer to calculate porosity from the neutron log proved an effective, rapid means for evaluating a large number of logs. Saturation calculations from electrical logs were used as a check on capillary determinations, and the results of the two different methods were substantially in agreement.
The methods outlined should result in a more accurate estimate of reservoir fluid content and a better understanding of reservoir performance.

Introduction
The engineering study of an oil reservoir has as its major objectives (1) the determination of the types and quantities of fluids in place at the original reservoir conditions, (2) the determination of the productive forces active in the reservoir, and (3) an estimate of the fluids which will be produced under various methods of operation. Particularly during the early life of an oil field, the original contents of the reservoir can be estimated most accurately by determining the volumetric and saturation parameters of the intervals being exploited. For this purpose core analysis and various types of well logs are in general use.
Gamma Ray-Density Logging
Authors: Zak Albin J. , Smith Joe Ed 
Published: February 2020

Permian Basin Oil Recovery Conference, 7–8 May, Midland, Texas

Abstract
This paper presents a review of current methods of interpreting and applying gamma ray-density logs in evaluating fundamental reservoir data. The basic theories and physical principles underlying the techniques of density logging with gamma rays are discussed along with some of the problems associated with the instrumentation of such a tool. An effort has been made to evaluate the instrument calibration techniques, and discussion and figures are presented which describe the effect of borehole conditions, pressure, temperature, etc. The relationship of natural density, grain density, and interstitial fluid density to porosity is presented. Field data illustrate how density logs can be correlated with porosity and grain density data. With the aid of adequate core analysis data, a reasonably accurate estimate of formation porosity can be obtained from density log interpretation. The paper also offers a discussion of the limitations of the density log as a porosity tool. The current applications of the density log to geologic work are cited, and the prospective uses and future developments are briefly explored.

Summary
The principle of gamma ray absorption as a function of density was adapted to the logging of petroleum formations through the utilization of a phenomenon known as "back-scattering". This technique uses a tool which contains both a gamma ray source and detector. The detector measures the intensity of the gamma rays emitted from the source that have been back-scattered to the detector by the formation. After proper instrument calibration, the log response can be used to compute the natural density of the formation. Since there is a definite relationship between natural density and porosity, it is possible to predict formation porosity from density logs. It is necessary to correlate carefully density log data with core analysis data before the direct correlation of density log response with porosity can be made.