bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Formulations for the Team Orienteering Problem
Authors: Derya Tusan , Kara Imdat , Bicakci Papatya Sevgin , Kececi Baris 
Published: April 2017

Routing problems have many practical applications in distribution and logistics management. The Traveling Salesman Problem (TSP) and its variants lie at the heart of routing problems. The Orienteering Problem (OP) is a subset selection version of well-known TSP which comes from an outdoor sport played on mountains. In the OP, the traveller must finish its journey within a predetermined time (cost, distance), and gets a gain (profit, reward) from the visited nodes. The objective is to maximize the total gain that the traveller collects during the predetermined time. The OP is also named as the selective TSP since not all cities have to be visited. The Team Orienteering Problem (TOP) is the extension of OP by multiple-traveller. As far as we know, there exist a few formulations for the TOP. In this paper we present two new integer linear programming formulations (ILPFs) for the TOP with O(n2) binary variables and O(n2) constraints, where n is the number of nodes on the underlying graph. The proposed formulations can be directly used for the OP when we take the number of traveller as one. We demonstrate that, additional restrictions and/or side conditions can be easily imported for both of the formulations. The performance of our formulations is tested on the benchmark instances from the literature. The benchmark instances are solved via CPLEX 12.6 by using the proposed and existing formulations. The computational experiments demonstrate that both of the new formulations outperform the existing one. The new formulations are capable of solving optimally most of the benchmark instances, which have solved by using special heuristics so far. As a result, the proposed formulations can be used to find the optimal solution of small- and moderate-size real life OP and TOP by using an optimizer.

Keywords: Traveling salesman problem, orienteering problem, modeling;
The Robust Learning Model With A Spiral Curriculum: Implications For For TThe Educational EffectivenessOfOf Online Master Degree Programs
Authors: Neumann Yoram , Neumann Edith , Lewis Shelia 
Published: April 2017

This study integrated the Spiral Curriculum approach into the Robust Learning Model as part of a continuous improvement process that was designed to improve educational effectiveness and then assessed the differences between the initial and integrated models as well as the predictability of the first course in the integrated learning model on a wide range of educational effectiveness indicators for online master degree programs. Meaningful improvement in educational effectiveness was validated by the study. The importance of the first course's predictors in predicting and explaining the various degree program educational effectiveness indicators was also very instrumental. The theoretical and practical implications of the study's findings for online faculty, university administrators, and policy makers were examined.
Using The Internet In Teaching Algebra To Middle School Students: A Study Of Teacher Perspectives And Attitudes
Authors: Alsaeed Maha Saad 
Published: April 2017

During the past decades, technological resources have been improved to support the teaching of mathematics. While the improvement of technological resources, the World Wide Web provides teachers and students many resources that engage students in rich mathematics experiences. There are a vast number of educational resources available through the Internet for students and teachers, which should be implemented in the classroom to support and improve algebra instructions. This study seeks to identify the extent of the middle school teacher’s awareness of using the Internet to teach and develop students’ learning of algebra. The participant’s teachers in this study are teaching in schools located in a rural Appalachian region of a Midwestern state in the United States. The study found that the Internet’s function in the algebra classroom within this particular group of middle childhood teachers are used for purposes that do not contribute to algebra instruction.
Innovation Policy And Governance In The African Region
Authors: Gachie Wanjiru , Govender Desmond Wesley 
Published: April 2017

This paper undertakes a desktop examination of innovation policy and governance in Africa. The article therefore adds on to the importance of intra-African region innovation policy dialogue by exploring policy developments in the African region. The article identifies a weak and fragmented innovation system as a major challenge facing many of the African countries, exacerbated by the lack of an explicit innovation strategy. The literature indicates that Science, Technology and Innovation (STI) policies should not simply adopt a science-push approach to innovation, but rather focus on building an entire system of innovation. The emergence of a knowledge-based economy and globalisation such as the BRICs - Brazil, Russia, India, China and South Africa are restructuring the dynamics of innovation in developing countries. The literature has also shown that several international organisations have played significant roles in the development of Science and Technology (S&T) policies among African countries. However, the international organisations initiatives have mostly focused on the development of S&T with minimal emphasis on the role of policies and administration, which would increase learning and innovation performance in Africa. The central premise of the article is that innovation policy and governance is an essential component of the National System of Innovation in the African region.
Marginal Employment Growth Effects In The South African Economy
Authors: Kaseeram Irrshad , Mahadea Darma 
Published: April 2017

South Africa relative to its peers (upper middle income countries) suffers from high unemployment and sub-optimal economic growth. This study investigates the ‘marginal effects of employment’ with respect to real output and capital in South Africa, using annual data covering the period 1946-2015. It estimates the responsiveness of employment to real output growth and capital, employing the short and long-run dynamic interactions between these variables via the application of the VAR/VECM Johansen (1991) framework. The results show that there exists a statistically significant long-run co-integrating relationship between labour employment and real GDP growth. Marginal employment growth effect is positive; a one per cent increase in GDP tends to increase employment by about one third of one per cent. Employment adjusts consistent with expectations when it overshoots its structural relationship with other variables. However, real output tends to adjust contrary to expectations, implying significant diminishing returns to employment in the economy. Growth in capital impacts positively on output and employment. The study concluded that greater labour market flexibility and higher worker productivity is needed across all sectors of the economy.
Unplanned Readmissions Following Outpatient Hand and Elbow Surgery
Authors: Noureldin Mohamed , Habermann Elizabeth B. , Ubl Daniel S. , Kakar Sanjeev 
Published: April 2017

Background:
Unplanned readmission following surgery is a quality metric that helps surgeons assess initiatives targeted at improving patient care. We utilized the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to determine the rates, causes, and predictors of unplanned 30-day readmissions after outpatient elective hand and elbow surgery.

Methods:
The ACS-NSQIP database was queried using hand-and-elbow-specific Current Procedural Terminology (CPT) codes to retrospectively identify patients who had undergone outpatient hand or elbow surgery in 2012 and 2013. Patients who required an unplanned readmission to the hospital within 30 days were compared with those who were not readmitted. Preoperative patient characteristics, intraoperative variables, complications, and mortality were compared between the cohorts. Cox proportional hazard models were used to determine independent associations with 30-day unplanned readmission.

Results:
A total of 14,106 outpatient hand or elbow surgery procedures were identified between 2012 and 2013, and 169 (1.2%) of them were followed by an unplanned readmission. The leading causes of readmission included postoperative infections (19.5%), pain (4.7%), thromboembolic events (4.1%), and pulmonary complications (3.0%). The causes of approximately 1/3 of the readmissions were missing from the database, and these readmissions were likely unrelated to the principal procedure. Independent predictors of readmission included an age of 70 to 84 years (hazard ratio [HR] = 2.83, 95% confidence interval [CI] = 1.67 to 4.78), smoking (HR = 2.23, 95% CI = 1.57 to 3.18), a lower hematocrit (HR = 2.19, 95% CI = 1.38 to 3.46), renal dialysis (HR = 3.32, 95% CI = 1.60 to 6.91), and an elbow procedure (with or without a hand procedure) (HR = 2.19, 95% CI = 1.57 to 3.04).

Conclusions:
The prevalence of unplanned readmission following outpatient hand and elbow surgery is low. Several modifiable factors, including preoperative smoking and anemia, are associated with unplanned readmission. These data may be helpful in developing quality-control initiatives to target unplanned readmissions following hand and elbow procedures.

Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Exposición a la publicidad de tabaco y consumo de tabaco en adolescentes en América del Sur
Authors: Plamondon Geneviéve , Guindon Emmanuel , Paraje Guillermo 
Published: April 2017

Objetivo. Este estudio evalúa la relación estadística entre la exposición a la publicidad de tabaco y el tabaquismo en los adolescentes de América del Sur. Material y métodos. Usando datos de la Encuesta Mundial de Tabaquismo en Jóvenes (GYTS) se estudiaron los niveles de exposición a nivel de escuela, ante distintos tipos de publicidad, además se evaluaron los comportamientos asociados al tabaquismo durante la experimentación y consumo. La muestra total fue de 134 073 jóvenes de Argentina, Bolivia, Chile, Perú, Brasil, Uruguay, Surinam, Colombia, Guyana, Ecuador, Paraguay y Venezuela que se combinaron en el análisis. Resultados. La exposición a la publicidad está positiva y significativamente asociada a un incremento en las probabilidades de que los jóvenes experimenten con el cigarrillo al menos una vez en sus vidas. Para los fumadores activos, la exposición a la publicidad está positiva y significativamente asociada con el número de cigarrillos fumados. Conclusiones. La publicidad de productos de tabaco debe ser controlada fuertemente o eliminada totalmente en varios países de Sudamérica.
Technology Focus: Seismic Applications (March 2017)
Authors: Egan Mark S. 
Published: April 2017

Technology Focus
My career in the oil and gas industry started in 1975. Shortly thereafter, a theme that became wildly popular in conferences, workshops, and internal boardrooms was better integration of seismic with other oilfield disciplines. Initial progress was slow, but, if we fast-forward to today, we see that significant strides indeed have been made. A good representation of integration papers appeared this past year, so that is the theme we will use.
Advancement of the integration of seismic with other oilfield disciplines has been fueled by two factors. First, evolutionary advances in seismic technologies naturally led to more-powerful integration. A simple example is the progress made in bandwidth. In this regard, advances in seismic sources, field recording equipment, and data processing all benefited interpretation, inversion, and reservoir modeling. For example, in the 1980s, a commonly used vibrator sweep in land surveys was 12–48 Hz. Today, sweeps start as low as 2 Hz and often go up to more than 100 Hz. The benefits to resolution and derisking have been striking.
Second, several developments in seismic were motivated in direct response to the needs of interpreters and engineers. For instance, the appearance of creative, new, high-channel-count survey designs provided full-azimuth, densely sampled data that led to striking advances in imaging complex structures (especially in subsalt settings) and provided the wherewithal for characterizing natural fractures and stress in both conventional and unconventional plays. Indeed, this tighter integration of seismic with geomechanics energized the rise of the microseismic technique.
Six integration papers were selected. Three are presented here in summary format, and three are listed for additional reading. They come from all over the world, cover a range of reservoir lithologies, and deal with a suite of geologic settings. Let’s keep the progress moving.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 183289 Seismic Reservoir Characterization of Carbonate Reservoirs—Case Study of the Mishrif Formation, Zubair Field, Iraq by J.M. Rodrigues, Eni, et al.
IPTC 18956 Seismic-Driven Lithofacies for Geological-Model Infilling in a Deep Offshore Turbiditic Field—Case Study by Victoriano Da Silva, Total E&P, et al.
SPE 181872 Microseismic Mapping Improves Understanding of a Complex Reservoir: A Case Study in a Southern Sichuan Shale Gas Field by Yang Wang, Halliburton, et al.
3D Close-the-Loop Method Based on Probabilistic Seismic Inversion
Authors: Carpenter Chris 
Published: April 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 18913, “3D Close the Loop Using Probabilistic Seismic Inversion for a Gas Field in the Carnarvon Basin, Australia,” by Shilpi Srivastava, Jeroen Goudswaard, Sito Busman, and Justin Ugbo, Shell, prepared for the 2016 International Petroleum Technology Conference, Bangkok, Thailand, 14–16 November. The paper has not been peer reviewed. Copyright 2016 International Petroleum Technology Conference. Reproduced by permission.
The paper discusses an approach for predicting the lateral variation of net to gross (NTG) by use of 3D probabilistic seismic inversion. The goal is to define and understand the distribution of sands and shales on the basis of seismic reflection data. The modeling and inversion are supported by the good quality of seismic data. This study underpins the benefits of seismically constrained reservoir modeling. The use of probabilistic inversion to map geological features is a new insight in the applicability of this methodology.
Introduction
The study field is located in the Carnarvon Basin offshore western Australia. The field was appraised with one well, which has added incremental volumes to existing nearby discoveries. Seismically constrained reservoir-model building creates models that are constrained by, and matched to, geological concepts and seismic amplitudes and travel times. The complete paper shows an approach using 3D probabilistic seismic inversion to predict the lateral variation in NTG over a proven discovery. This, in turn, can be used to update the static-model properties, improving on the first-pass static-model build. Additionally, the inversion will aid in the understanding of some poorly understood seismic expressions, especially in the south of the field. In this area, the authors noticed dim amplitudes on the amplitude maps extracted from the seismic data, where the static model predicts the presence of the reservoir.
Field
The field is located in the Carnarvon Basin. The discovery was appraised by one well, which penetrated a thin sand layer of interdistributary bay reservoir facies (referred to as Sand 1) and a thicker distributary channel facies (referred to as Sand 2). The overburden comprises basinal shales and marls.
The main steps in the 3D close-the-loop work flow are
The rock-property-trend models are derived using the available vertical wells in or near the field. A “rock model” is a set of equations that honors well data and links the petrophysical properties such as NTG and porosity with rock acoustic properties.
A qualitative 3D check-the-loop (CTL) step is carried out. This involves the initial fit of the static model with the seismic data by forward modeling the synthetic seismic computed from the initial static model before inversion. The quality-control step that follows aims to detect mismatches between seismic and synthetic data.
Finally, constrain the reservoir model by use of the seismic data by carrying out 3D probabilistic inversion of the key uncertain rock property.
Fracture Modeling Using a Constructed Discrete Fracture Network From Seismic Data
Authors: Carpenter Chris 
Published: April 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 179130, “Calibrated Complex Fracture Modeling Using a Constructed Discrete Fracture Network From Seismic Data in the Avalon Shale, New Mexico,” by Foluke Ajisafe, Manoj Thachaparambil, Donald Lee, Ben Flack, Kim Hemsley, Efe Ejofodomi, and Christopher Taylor, Schlumberger, prepared for the 2016 SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, 9–11 February. The paper has not been peer reviewed.
The objective of this study is to validate the concept of using a seismically derived discrete fracture network (DFN) calibrated with borehole measurements, for complex-hydraulic-fracture modeling. This study was applied successfully on a two-well horizontal pad in the Avalon Shale located in the Delaware Basin, New Mexico. The work flow presented in this paper shows the successful application of seismic data in creating DFNs required to model hydraulic fractures in unconventional reservoirs.
Introduction
In the past, hydraulic-fracture modeling was limited to planar models for conventional reservoirs, with the absence of natural fractures. In unconventional reservoirs, planar models are highly limited in properly simulating complex fracture geometries. In recent years, a state-of-the-art complex- fracture-network model, also known as an unconventional fracture model (UFM), was developed. The model simulates the fracture propagation, rock deformation, and fluid flow in the complex fracture network created during a treatment. A key difference between the UFM and the conventional planar-fracture model is the ability to simulate the interaction of hydraulic fractures with pre-existing natural fractures.
In shale plays, conventional DFN models are built out of 1D fracture-dip interpretation from a borehole-image log or from core in the same or a nearby well. However, because the hydraulic fractures created during a stimulation treatment usually extend hundreds of feet away from the wellbore, it is important to characterize and understand the natural fractures away from the wellbore. Therefore, a more-accurate DFN model than the simple conventional model is crucial in unconventional plays for optimizing well spacing and stimulation design to ultimately achieve maximum effective drainage while maximizing returns.
In this study, the authors use an established work flow for extracting seismic-scale fracture networks and extending their population properties to model corresponding subseismic fractures that are critical to understanding and calibrating complex-hydraulic-fracture geometry created during stimulation.
Geology
The Avalon unconventional shale play consists of siltstone, limestone, clay, chert, and organics. It can be subdivided into three zones: upper, middle, and lower. In the past, the Avalon shale has been exploited by vertical drilling, but recently, horizontal drilling has been the trend to fully exploit this unconventional play.
El lenguaje, una herramienta para aprender mediante el modelo de gestión Aprendizaje Invertido, un estudio de caso en alumnos de 5º de primaria.
Authors: Centeno Flores Gabriela , Alcaraz Montaño Ana Lidia , González Herrera Oscar Rizieri , Oropeza Endoqui Karina Stefhania , Ramírez García Gabriela 
Published: April 2017

Estudio cualitativo sobre la implementación del Aprendizaje Invertido dando respuesta a ¿Cómo se implementa e impacta el Aprendizaje Invertido en el desarrollo de la competencia comunicativa: emplear el lenguaje como instrumento para aprender? A través de una estrategia de innovación basada en evidencia al aplicar el modelo de estudio de casos. Se obtuvieron los resultados a partir de la triangulación de la información generada de la observación activa y la entrevista estructurada a docentes y alumnos. Encontrando que la implementación del modelo construye ambientes de aprendizaje activos donde se abarcan los diferentes estilos de aprendizaje y el uso de las TIC, logrando impactar en el rol del alumno, en el desarrollo de competencias y en el impulso del pensamiento crítico.
Evaluación del desempeño de tres herramientas antiplagio gratuitas en la detección de diferentes formas de copy-paste procedentes de internet.
Authors: Díaz Arce Dariel 
Published: April 2017

El plagio académico se ha extendido en todos los niveles educativos. Para su identificación y corrección, se han diseñado múltiples herramientas informáticas, sin embargo, las de reconocido prestigio son comerciales y de difícil acceso a estudiantes y profesores de escasos recursos. El presente trabajo tuvo como objetivo fundamental evaluar el desempeño de algunas herramientas de acceso gratuito a través de internet. Se diseñó una búsqueda simple en Google con las palabras “herramientas antiplagio gratis” y “free antiplagiarism tools”, descartándose las que no permitiesen la revisión de un volumen mínimo de 20 trabajos por día. La evaluación se dividió en tres partes: la primera puramente cualitativa descartando todas aquellas que no cumplieran los criterios preestablecidos, la segunda implicó una evaluación cuantitativa preliminar evaluando un total de 17 trabajos con diferentes formas de plagio y la tercera evaluó con la metodología de las curvas ROC el desempeño de cada herramienta seleccionada frente a Turnitin como “prueba de oro”. El análisis mostró tres herramientas gratuitas con un desempeño aceptable para detectar copias de textos procedentes de internet: Small Seo Tools, DupliChecker.com y Search Engine Reports, siendo la primera la de mejor desempeño en condiciones reales. Los resultados muestran que la detección de trabajos en condiciones controladas los resultados puede diferir significativamente de las condiciones reales.