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This paper evaluates economically build a new cogeneration plant with clean energy from forest biomass company Norske Skog Bio Bio (NSBB). This is to show that this plant-based forest biomass for electricity generation is a viable option in Chile from the economic and environmental perspective. For this evaluation, we propose an approach that uses “real options theory" based on the application of log-transformed binomial method with six steps. Also, comparing the results obtained with this approach, the results using traditional methods. It is found that for all cases studied, the value yielded by the real options method was higher than estimated by traditional methods. It is concluded that this alternative profitable investment. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present, to those neophyte researchers, a set of hints that facilitate manuscript writing and publishing processes needed for high class scientific journals. In the scientific community, a research would only be completed when the results are shared through papers in peer-reviewed journals that guarantees the originality, importance and scientific validation of reported contributions. Consequently, researchers have the necessity to develop skills and abilities in scientific writing. However, the manuscript preparation process from the initial phase to the final publication is usually slow and difficult, due to some key factors having infiuence over its quality. In this paper, we present general guidelines about manuscript preparation and we give some hints about good scientific writing practices. The aim of these hints is easing the review done by the peer-reviewers in the evaluation process. In this sense, this work contributes to the newcomers in scientific research socialization. [ABSTRACT FROM AUTHOR]

This paper presents a review of the Demand-Side Management mechanism proposed for some utilities for residential load management. Also, this paper shows some Smart Appliances applications and Home Energy Management strategies developed and shown by some authors in the available literature that could be adequate strategies for improving Demand Respond inside the Smart Home context. Also, it is shown how Home Energy Management based on different Demand-Side Management strategies, could reduce peak load demand and save costs of power for end-users. Finally, the conclusions are presented. [ABSTRACT FROM AUTHOR]

Project Management Office (PMO) design and use have been mainly based on praxis; nowadays, there is a demand for more scientific support. Additionally, the scientific work on the subject has been focused on business scenarios. This article develops a conceptual model of the main functions of the PMO in educational scenarios and a validated instrument at the content level that makes them measurable. The methodology consists of four stages (identify, describe, deepen, disseminate), which incorporate the general protocol of a systematic review, the critical incident method, inter-judge agreement, and content validation with experts. The initial sample obtained by the search algorithm, implemented in Scopus and Web of Science, consisted of 26 papers in educational contexts. Of these, fourteen passed the inclusion/exclusion criteria. These papers were analyzed, described, and characterized, which allowed the compilation of 167 critical incidents (specific functions of PMOs in educational settings), which were the input for the deployment of the consensus among judges. This article discovers and describes seven dimensions that synthesize the main functions of PMO in educational settings and 47 items that reflect their empirical manifestations and meet properties of clarity and relevance. The model and the instrument clarify what PMO functions are, what they represent and how they can be measured in educational settings. They are valuable for teaching, auditing, planning, intervention/control, and research on the topic. [ABSTRACT FROM AUTHOR]

The modeling and prediction of time series is an arduous and essential task for financial optimization procedures. Numerous studies have been carried out to reduce investor uncertainty, by forecasting the price of currencies and shares. However, the emergence of a new type of coins with their own characteristics, known as cryptocurrencies, present additional challenges. In this sense, the paper seeks to understand up to what extent comments in social networks can capture the collective expectations of investors, and affect the future value of the currency. The objective is to predict the daily performance of a market based on two components: those that define the behavior of the cryptocurrency itself (volume, opening value, closing value, maximum value and minimum value) and the expectations and interactions of the environment, through the collected tweets. For this, the use of a type of recurrent neural network known as "Long Short Term Memory" (LSTM) is proposed. The methodology used for the preprocessing of the data and the application of this time series forecasting technique allows obtaining a prediction with a Mean Absolute Percent of 34.92%; This indicates that the representation of the perception variable in social networks has not been that relevant and, therefore, motivates new works for better representation using other NLP techniques. [ABSTRACT FROM AUTHOR]

The society of the 21st century requires training of engineers capable of solving problems in applications of the limit of real functions. In this paper, the mathematical skills of three engineering degrees belonging to the 2019 cohort of a public university is analyzed. The objectives of this study are to investigate the skills of undergraduate students in solving of mathematical problems, defined according to their nature in routine and non-routine, and according to their context, in real, realistic, fantasist and purely mathematical. Also, identify and characterize the types of problems addressed, and to solicit the opinion about the level of difficulty of the problems involving the limit of real functions and on the prior knowledge that they need to achieve a better performance in their resolution. Students from three different engineering programs volunteered to participate in the study. The evaluation tool used consisted of a function limit application problem solving test, which was content validated by eight experts in the field, and an open-ended opinion questionnaire. The results favor the performance of the students in solving routine problems in fantasist contexts, and even are guarantee development the mathematical skills necessary to solve non-routine problems of application of limits. [ABSTRACT FROM AUTHOR]

Learning curves have been frequently applied in production/operations management and various logistics processes in many manufacturing and service organizations. However, studies on their integral use in the supply chain are recent. This paper contributes to filling this knowledge gap by measuring the impact of learning on lead time in logistics management systems. The empirical study was used as a methodological tool to demonstrate this. The logarithmic-linear models, with their terminology and calculation equations, were applied to three case studies representatives of the logistics systems proposed by the Supply Chain Operations Reference (SCOR) model: make-to-order, make-to-stock, and engineer-to-order. As a result, the first two were adjusted to the Stanford model and the third to De Jong's model. Their learning curve, mathematical equations, and a sensitivity analysis were determined. This approach demonstrated its relevance and difference compared to previous publications, which mainly analyze links or parts of the CS. [ABSTRACT FROM AUTHOR]

This work shows a technical-economic procedure to determine the adapted network in a low voltage (LV) residential electrical system with photovoltaic distributed generation (PVDG). A network is adapted when it is designed to minimize the total fixed and variable costs and optimize the equipment to adequately satisfy the demand (both the current demand and its expected growth). The study will consider that the decision to install PVDG is exogenous. The method is based on the concept of Hosting Capacity (HC). This paper analyzes four typical LV networks in the city of Buenos Aires, Argentina. A statistical power flow solves the networks. We take the following statistical variables: residential load, PV penetration, PV power, and location. We obtain the statistical HC for each network, and the HC is used to carry out the technical-economic study of the network. Finally, we establish the adapted network for each level of penetration. The results show that, without PVDG penetration, there are different network options with different costs per km2. When PVDG penetration increases, the networks with the lowest cost per km2 are discarded (due to their FCE), and only the networks with the highest cost per km2 survive. Once 70% penetration of PVDG has been exceeded, none of the studied networks is considered an option.. [ABSTRACT FROM AUTHOR]

Knowledge transfer in software development teams allows their members' non-externalized knowledge to be collected, to form the organizational knowledge from a repository and share it among them. During this process, difficulties may arise in making this knowledge available, which may be associated with the lack of collaboration and motivation of the team, as well as poor communication and little support from the organization. Given these difficulties, the GamifiK strategy, supported by gamification, was proposed to foster collaboration in the transfer of knowledge in software development teams. This paper used an empirical research approach with a quasi-experimental design in an academic context to evaluate the collaboration of agile team members in sharing their knowledge and contributing to knowledge transfer. A statistically significant increase in team productivity was perceived, reflected in the ability to perform more user stories per sprint and complete incidents in less time. GamifiK is a promising strategy for fostering collaborative knowledge transfer across software development teams. [ABSTRACT FROM AUTHOR]

This paper presents a study of magnetic flux density in a large synchronous large size machine when it is working as a generator. Finite elements software has been used to obtain the same physical and electrical characteristics of the real machine. From the results conveyed from the simulations, it is possible to find the optimal points where the magnetic flux sensors will be placed and to determine short-circuit faults in the rotor coils. The work results are also a reference to evaluate and compare the magnitudes taken by the sensors without creating short-circuits in the actual machine coil. Besides that, the proposed model based on finite elements can be used to make simulation tests of new kinds of sensors. [ABSTRACT FROM AUTHOR]

This paper presents the modelling and simulation of a complex system applying the hierarchical coloured Petri nets method to represent the failure and repair processes, as well as obtaining statistical data indicating its performance. The simulation was performed on the model of a mechanical system characterized by the FAMAE SG 542-1 war rifle, commonly used in the Chilean Army, through the CPN Tools and Python software representing how components perform of operation of this weapon. This behaviour is recorded through both software, obtaining the simulation data so that it will be possible to predict the condition of a component and the system in the future to generate corresponding action plans. [ABSTRACT FROM AUTHOR]

In this paper, the structural seismic performance is evaluated by nonlinear analysis according to the ASCE/SEI 41-17 methodology, and the probability of collapse of structures subjected to 11 ground movements, scaled to hazard levels corresponding to serviceability, design, and maximum considered earthquakes, is determined. Three-dimensional Finite Element Models (FEM) of one, two, and threestory frame structures are evaluated subject to eleven different ground motions, selected and scaled to represent these hazard levels. Following the methodology mentioned earlier, collapse probabilities are estimated for RC frames typical of Ecuador. Structures in this study are divided into two categories: Those designed according to seismic-resistant engineering practice and those built without engineering design. For each category, infilled and non-infilled frames are distinguished. Infill masonry negatively impacts structural performance and the collapse probability of frame structures. Damages observed during previous earthquakes are consistent with the results of this study. [ABSTRACT FROM AUTHOR]

The present article proposes a system of a quantitative assessment of the ability of inspectors to make correct decisions, applying an R&R study by attributes, with the method of risk analysis, supported by contingency tables and the Cohen Kappa index. Additionally, it establishes a tool to simplify the required calculations and a proposed inspection method that seeks to reduce the variability associated with the inspection process. In this paper, a simulation study is made. We simulate several quality inspectors and three sceneries. Results show a quality level between 95% and 99% was obtained. It is possible to show that reducing the variability of inspection processes results through standardized methods, criteria equalization, and staff training improves the quality level process. The procedure presented and simulated in this article can be applied in the qualitative inspection, such as manufacturing processes as services processes. [ABSTRACT FROM AUTHOR]

Due to the constant growth of global environmental pollution, the sectors related to the electrical industry have focused on finding solutions to achieve efficient energy consumption. Among the devices that have been incorporated to carry out improvements in electricity consumption are smart sockets. This paper presents a prototype for a general-purpose smart socket. The design considers the main components of a smart plug: measurement unit, control unit, processing unit, and communication interface. The prototype is based on free hardware, with easy access, low cost, and consumption. This work successfully developed a device capable of measuring, controlling, and monitoring the electrical behavior of equipment connected to the power grid. Additionally, it incorporates temperature, light, and humidity sensors to complement the electrical measurements. The prototype presented offers the possibility of developing many functionalities and services aimed at energy efficiency on the topic of the Internet of Things (IoT). [ABSTRACT FROM AUTHOR]

In software development, smells are parts of source code that suggest a deeper problem in the system such as duplicated code. Specific knowledge and skills are required for identifying, correcting, and preventing bad code (smells) in the software development process. Such knowledge and skills can be learned, trained, and tuned. Some researchers have evidence about the usage of educational games for motivating, teaching, training, and improving several skills. By using principles of educational games, some authors propose strategies for software development teams to adopt good practices, but these proposals suffer to show different types of code smells and strategies to correct them. In this paper we propose Smellware as a game for teaching best practices in the software development process. The paper describes the game structure and the results of its app. ication in students of software engineering. This proposal aims to strengthen the skills of software developers for identifying and addressing several types of bad code smells and raise awareness about the effects of these bad practices in software development. [ABSTRACT FROM AUTHOR]

Games for educational purposes have been used in different areas as supplementary strategies to the traditional teaching-learning process. Software Engineering-applying methods and techniques for building high-quality software products-also includes games in the professional training process. In order to provide a tool for teacher guidance about their use in their teaching-learning process, several game classifications have been proposed. However, existing classifications consider the game purpose and the target audience, but they omit variables associated with the structure of the game-e.g., rules or materials. This paper proposes a classification of games for teaching software engineering considering purpose, scope, and fun components. This proposal defines the key features of any game for teaching software engineering and provides alternatives to professors for incorporating this teaching tool in their training process. The proposed classification was applied to a set of 17 games oriented to software engineering teaching, showing its potential as a support tool in the analysis, comparison, and selection of games for teaching this discipline. [ABSTRACT FROM AUTHOR]

There are multiple technologies for transporting info-communications between objects and machines for the internet. Two of the most robust and with the highest coverage and support for multiple users are 4G and WiMax IEEE 802.16x. This paper presents a simulation of land coverage of both wireless communication technologies as a broadband communication alternative for new free, private, or supported operators by public institutions, such as municipalities or regional cooperatives. The cases of the cities of Riga, Bucharest, Florianópolis, Santiago, Concepción, and Copiapó were studied. The study uses Radio Mobile GLOBE-BIL software, obtaining propagation coverage graphs on digital SRTM terrain elevation maps released by NASA. This simulation determines the number of antennas required for millions of users in the context of the Internet of Things. It quantifies the square kilometers of wireless propagation coverage that can be technically achieved for each project city. The results show that WiMax supports a more significant number of connected users, has better coverage, and requires fewer antennas. On the other hand, for the propagation coverage indicator, the results for 5 cities are better for WiMax technology than 4G, except for Santiago (Chile), where the best performance is achieved for 4G over WiMax. [ABSTRACT FROM AUTHOR]

Balancing methods for mechanisms have been used over the years to extend the lifespan of machinery by reducing vibration, wear, and fatigue on their components. These techniques have grown in effectiveness but also in mathematical complexity. Nowadays most balancing methods use Cartesian coordinates, which generate complex equations involving trigonometric functions that are difficult to simplify. This paper presents the use of natural coordinates to obtain the balancing parameters of a simplified crankconnecting rod-slide mechanism avoiding the use of trigonometric functions. The balancing optimization of the mechanism is carried out by using a stochastic optimization algorithm based on populations allowing to reduce the Shaking Moment (ShM) by 97.76% and the Shaking Force (ShF) by 94.58%. [ABSTRACT FROM AUTHOR]

This paper analyzes three path planning techniques to solve a ball-maze system with a two-degree-offreedom platform. The system's objective focuses on the ball traveling a path from an initial point to a final point (defined by the user) in the maze. The RRT algorithms (Rapidly Exploring Random Trees), PRM (Probabilistic Roadmap), and Voronoi diagrams were implemented using the A* search algorithm. The system architecture consists of four subsystems called mechanical, vision, planning, and control. The main contribution of this work is the evaluation of the algorithms on a physical system and a complete results analysis (graphical and analytical). The experimental tests were performed based on analyzing four different maze configurations, the run time, and path length metrics. In this context, 20 algorithm executions were developed for each configuration, then the meantime and mean length and their 95% confidence intervals were determined. The main results show that the RRT algorithm presents a more significant variation in its data, the longest path length, and the best performance in terms of run time. Moreover, the PRM algorithm generates the path with the shortest length but has the worst performance concerning run time. Finally, the Voronoi diagrams' technique takes less time to execute, has less variation in its data, and presents the smoothest and equidistant path between the maze walls. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the relationship between leadership and performance in teams of higher education students. For this, first, we conceptualize leadership as an influence process between team members and, second, we model this team process using social network analysis. To study the proposed relationship between leadership and performance, we conducted a study at 164 students of 41 teams of industrial engineering students of two universities in Chile. We analyzed our data using linear regression analysis, and our results showed that leadership network density is positively related to performance, and leadership network centrality is negatively related to performance. These results help teachers, and higher education institutions have a reliable statistical tool to track student leadership development throughout the curriculum. [ABSTRACT FROM AUTHOR]

Proportional-integral-derivative (PID) controllers are widely used in industrial control systems and control theory academia, mainly due to their functional simplicity and robust performance. This paper presents the performance comparison of a PID controller, implemented with two different technologies, (i) a SIEMENS SIMATIC S7-1200 programmable logic controller and (ii) an embedded system based on RASPBERRY PI. The parameters were set with the same conditions for both technologies. The control was performed on a level system on the platform located in the process control room and computerized systems at the Electricity and Industrial Automation Center (CEAI), SENA in Valle del Cauca, Colombia. The results obtained indicate that, for both technologies under the same conditions, the controllers have the same performance in terms of settling time, rise time, delay time, peak time (time where the maximum overshoot occurs), and steadystate error. Makeover, they differ in the control effort where the PLC performs 2.10% less control effort than the embedded system and a signal overshoot of 2.05% compared to 4.32% of the embedded system. These results show that controller implementation with an embedded system is an excellent low-cost alternative for industrial processes with similar results as a controller implemented in a PLC. [ABSTRACT FROM AUTHOR]

The benefits of implementing Demand Response (DR) programs in large consumers have been widely documented. However, it is still necessary to explore in more detail the impacts of the implementation of these programs in residential users on the benefits of the distribution system operators. In this paper, we determine the effects of Demand Response (DR) on the reconfiguration of a distribution system considering the consumption characteristics of residential users in Colombia. For this purpose, the demand curve of a typical residential user was constructed for Bogotá D.C., and measurements were taken to estimate the participation of this user in a DR program. In addition, an algorithm based on Particle Swarm Optimization is used as a solution strategy for the reconfiguration problem. The results show that a distribution system reconfiguration could significantly increase the revenues obtained by a Network Operator. However, it is shown that the reduction of energy losses obtained from the DR would not provide sufficient incentives for them to promote the participation of residential users in this kind of programs. [ABSTRACT FROM AUTHOR]

The Lean construction philosophy has been welcomed by numerous companies in Colombia for a little more than a decade. The Last Planner System (LPS) is among the implemented tools found, a planning and control system that seeks to accomplish a continuous workflow. The system implementation results vary from one company to another, and there is no investigation to date that shows the diagnosis of the adoption of this tool in the country. This paper aims to illustrate the degree of implementation and functioning of the LPS from different perspectives found in sixteen Colombian construction companies. Data collection was carried out through non-participant observation during the weekly planning meetings, surveys conducted to construction professionals, supervisors, subcontractors and labor, and a semi-structured direct interview with the managers of the Lean area in the companies. Analysis of compiled information shows multiple ways of applying this tool, conceptual and practical failures, and a lack of training and permanent feedback that does not allow to be a part of the corporate culture were all identified. [ABSTRACT FROM AUTHOR]

The purpose of this paper has been to investigate the relationship between intellectual capital (IC) and financial performance, based on two constructs, human capital (HC) and relational capital (RC), measured in financial terms. The methodology was applied to a sample of Universities of Chile. This was done at public and private universities during the 2014-2018 periods. In this investigation, we used descriptive statistics, level of correlation, and panel data analysis to demonstrate the existence of a positive relationship between each component of IC and the performance of universities, measured in terms of financial performance. The panel results confirm the hypothesis that HC and RC positively impact the university financial performance (return on equity, ROE, and return on assets, ROA). The article contributes to improving the conceptualization of Intellectual Capital and its relationship with the financial performance of Universities. [ABSTRACT FROM AUTHOR]

In this paper, a computer vision inspection methodology is presented for the detection and segmentation of areas of wear by electric arc on the surface of electrical contacts using segmentation by instances. Cadmium is a toxic metal frequently used in the manufacture of alloys for electrical contact, so efforts have been made to replace or eliminate this element from the industry. Our work proposes an approach oriented to the automation of the inspection process, which reduces the subjectivity of the repetitive task of inspecting electrical contacts, allowing to compare two different alloys, such as one with Cadmium (Cd) and the other with Copper (Cu)., subjected to the same conditions and determine which of them presents less wear by electric arc. In this way you can know if the new part is better, equal or worse in terms of performance. Initially, an adaptation was made of the source code hosted in a github repository of mask R-CNN of the Matterport corporation, where variables, classes were modified, and directories were created according to our needs. The results obtained show that the masks generated by the algorithm adjust very well to contact wear, despite the irregular shape of the damage. However, the "charred" edge was probably not considered, because in training images it was a feature that few images presented, so segmentation may not be considering this factor. [ABSTRACT FROM AUTHOR]

This paper presents comparison of Standardization and Scaling methods in cost predicting. Four methods were used for pre-processing dataset; after that, data was processed through artificial neural network (RNA). The first step was to build common variables in information projects based on opinions of some project managers. Second step was to simulate dataset based on information provided by CRConsulting. Third one was process data with machine learning according to the four methods proposed, RNA algorithms were the same in four cases. Last, the comparison results were presented through adjustment models according to the applied method. [ABSTRACT FROM AUTHOR]

In this paper, a conceptual model for technical microgrids conception applied to a case study in Colombia is presented. The model considers aspects as: medium voltage electrical system topology setting, preselection of generation technologies, electrical demand prioritization, generators location employing the voltage Stability Index (SI), operation strategies and capacity sizing of distributed generators, components modeling and the evaluation of microgrid performance in aspects as voltage profiles and optimal power management. The conceptual model developed was applied in a case study for the Valle del Cauca region, Colombia, which presents urban and agroindustry areas suitable for the research requirements. For the microgrid steady-state performance evaluation, the computational tool of power systems analysis Neplan® was used. [ABSTRACT FROM AUTHOR]

University dropout is a problem related to the student, as a direct responsible, and with the university institution, knowing the possibilities of attrition is relevant for the institution. In this paper, it is proposed to use classification models to find patterns and predict possible dropouts in university students. An application has been implemented that uses information provided by the university and that generates classification models from different algorithms (neural networks, ID3, C4.5), and uses the most significant attributes within the available information. The performance of these models was compared to define the one that provided the best results and that will be used to classify the students. The results show that the algorithm of C4.5 presented improvements in performance with respect to the neural network and the ID3 and that the relation of credits approved by a student related to the credits that he should have taken is the most significant variable in the construction of the model, followed by the qualifications, while the modality of the admission exam through which the student entered the university did not turn out to be significant, since it does not appear in the generated decision tree. [ABSTRACT FROM AUTHOR]

Maintenance approaches have been evolving from reactive to a preferred proactive conception with operational reliability as a new implemented strategy. This scenario suggests that a review of conceptual basis is needed. The paper resumes the study carried out with the main objective of building a new concept of operational reliability. Bibliographic research and poll methods were used. Selected specialists with remarkable profiles in Microsoft Academic Search, Google Schoolar and Research Gate were consulted in order to validate the formulated concept. A poll instrument based on Likert Method was designed whereas for analyzing the confidence, Cronbach Alpha Method was used. As a result, a novel concept of operational reliability was built and validated. This concept sets up a synergic based relationship among equipment, human resources and technological processes and, for the first time, provides support to obtain an indicator as a numerical representation of operational reliability. [ABSTRACT FROM AUTHOR]

This paper presents the review of three main existing agile approaches: Scrum, Lean Software Development and Kanban, which served as the basis for the development of a proposal for a new approach in Agile development. To achieve this, a description of each agile approach to software development and a comparison of their strengths and weaknesses are made. Then, the new proposal is established based on the integration of the three approaches, defining a set of metrics and developing a case study to evaluate the integration and obtain quantitative and qualitative data. The results obtained from the case study proved to be quite positive because it allowed us to comprehensively evaluate the new approach. These results represent a promising start to continue working in this line of research. [ABSTRACT FROM AUTHOR]

The growing worldwide energy demand requires the design and construction of increasingly efficient generation systems. In satisfying this need, control schemes play an essential role. Having a system that allows experimental evaluation of their performance is key. In the case of wind energy, one possible control strategy is pitch regulation, which is used in variable pitch wind turbine systems. This paper presents the results of the design and construction of a testing bench for carrying out the experimental evaluation of control strategies for pitch regulated small wind turbines. Rotor operation and pitch regulation were ascertained through wind tunnel testing. Rotors start moving with winds of 3.5 m/s. PI and fuzzy controllers were implemented and tested. [ABSTRACT FROM AUTHOR]

The purpose of the performance evaluation is to measure the degree in which an employee of an organization adjusts or complies with the desired profile. The results of this measurement allow generating recommendations to improve the performance of the functions by the employee. Moreover, the results favor the human talent management, related to professional growth, bonuses, compensations, and candidate selection. In this paper, an analysis, comparing, and characterization process of the performance evaluation methods are presented. This process was realized to take advantage of the benefices of performance evaluation and identify which methods of performance evaluation are most used in software development teams. This analysis allows us to characterize these methods and identify the factors that determine their usage, as well as the criteria that allow them to specify and differentiate their application in the software industry. A methodology is integrated into three phases to carry out the purpose of this work. Through this methodology, it was possible to conduct the characterization of performance evaluation methods for software development teams. We identified 11 conventional performance evaluation methods and 10 approaches to performance evaluation for software development teams. We included conventional methods because the particular proposals for software development teams use some of them. From this set of studies, the analysis of characterization and comparison factors was established. This characterization shows that the evaluation of technical competences takes precedence, over generic, psychological, or experience competences. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study, which compares the effect of the sensitivity against the cementation in the recovering of the stress-strain properties in clayey soils from "Sabana de Bogotá". The work methodology included three phases: (i) extraction of samples; (ii) properties assessment of the undisturbed samples; and (ii) stabilization and analysis of the resistance of the stabilized samples with cemented materials. An experimental plan, which included physical and mechanical tests, was developed. The plan had an emphasis on the assessment of the undrained shear strength and the elastic modulus through unconfined compression tests. The samples were compacted and stabilized with the addition of two solid chemical products, calcium carbonate and iron oxide. Results between natural, remoulded and stabilized were compared by means of statistical methods. Therefore, it was found that the use of iron oxide in this kind of soil allows obtaining stress-strain parameters close to the undisturbed state after the compaction process. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the influence of the cutting speed, feed per tooth and machining strategy; on geometric quality of the machined surface, in the ball milling tool of the surgical grade titanium Ti6Al4V (In this paper, geometrical quality, is considered; parameters of surface roughness, dimensional accuracy and shape tolerance). The samples were machined by means of ball milling tool. Analysis of the influence of the factors was performed by means of a 2³ factorial experimental design. Further, an ANOVA (analysis of variance) was performed between concave and convex spherical geometries of the same radius, to determine the influence on the machined surface geometric quality geometric quality of the machined surface. Additionally, an ANOVA was performed; between convex spherical geometries different radius to determine the influence on the geometric quality of the machined surface. The factorial experimental design results showed that machining strategy factor on surface roughness parameters Ra. Furthermore, On the other hand, the ANOVA for the concave and convex spherical surfaces shows that the change from concave to convex surface influences geometric tolerance. Finally, ANOVA for convex spherical geometries shows that the radius changes influences surface roughness Ra, Rq and Rz, geometric tolerance and the dimensional accuracy. [ABSTRACT FROM AUTHOR]

Falls are the second cause of death in the world. This is the reason why systems of falls detection, framed in the telemedicine field, are widely investigated nowadays. However, these systems often result in false positives. In this paper we propose the development of a fall detection system for people. The system is based on the use of a Kinect 2.0 sensor that allows monitoring from one to six patients and an alarm system that sends both a message and an image to the e-mail of the person who is taking care of the patient. The biomechanical analysis of the fall, carried out using iPi Mocap Studio program, and the fall detection algorithm, developed in LabVIEW graphic programming software, allowed measuring the position and velocity values of a selected point in the skeletonization of the person. Different actions were simulated, including walking, sitting, bending and falling. From the position of the point-selected point (spinebase) of the skeleton of the person, the velocity was calculated with the derivative. This characteristic allowed defining the linguistic variables and fuzzy sets to classify the type of movement. The system was validated with 3 people, of different ages and heights, in a controlled environment, achieving an effectiveness of 95.8% and the activation of the alarm system, creating a technological assistant of adequate and reliable aid that guarantees the integrity of the patient. [ABSTRACT FROM AUTHOR]

This paper presents the design, simulation and implementation of a small scale battery charger with low harmonic distortion in current. It was proposed a design composed of two boost converters in cascade, the first operating as PFC and second as a regulator of the injected current to the batteries. Additionally, it was presented the procedure for the controllers design of each stage. In the first stage was used a control in average current mode and in the second stage were used two controls that enable you to employ the method of constant current - constant voltage in order to charge the batteries. In both stages were used the PI controllers and with the power electronic circuit were simulated in the PSIM® and MATLAB® software and validated experimentally In this tests, power factors close to 0.98 and harmonic distortion in current below 10% were obtained, complying with the requirements of the IEC 61000-3-2 standard. Finally, the conclusions are presented. [ABSTRACT FROM AUTHOR]

Currently, the software development industry presents challenges for processing business information, specifically that contained in textual documents. In the process of software requirements elicitation, a potential source of relevant information is business documents, since they can facilitate the knowledge understanding about a domain, as well as know the evolution of a product. Despite its usefulness, requirements engineers do not always use it for their work because of time and costs involved. In this paper this problem is addressed and it is recognized through a systematic literature review, the potentiality of using Natural Language Processing (NLP) techniques to extract relevant textual information from business documents, and the utility of its representation in conceptual models. Starting from this, a semiautomatic method of extracting information from business documents written in natural language in Spanish and its representation in a conceptual model is proposed. The method is supported in a reference methodological framework for Text Analytics projects, is based on NLP techniques, and the output is represented in a class diagram. The method was evaluated through a case study with software analysts in Medellin-Colombia, taking as input telecommunications resolution documents. The evaluation allows us to conclude that the model is a satisfactory approach to solving the problem, and some lines of work are identified to generalize a solution. [ABSTRACT FROM AUTHOR]

This paper presents multitasking programing of a three-phase speed variator development. This focus has not been reported in technical literature, although it is relevant for engineering power electronics developers, students, and researchers. Hybrid multitasking programing is proposed for the implementation of task that speed variator must carry out. Needed tasks in the speed variator are described and programed in a microcontroller (dsPIC30F4012) using state machines, considering times and priorities with preemptive and cooperative multitasking. This paper proposes a programing form for speed variator that allow software develop since its early stage. The programing structure enables the use of microcontrollers with lower performance. Thus reduction of production costs could be achieved. A three-phase speed variator is presented that can change output-voltage frequency and amplitude without stops or interrupts. Validation of multitasking programming is done on an experimental prototype developed in the laboratory, evaluating the execution times of tasks. [ABSTRACT FROM AUTHOR]

This paper presents a structural equations model (SEM) that measure the Urban Quality of Life (UQoL), taking as reference Cienfuegos's city (Cuba). The objective is to determine the variables that influence the UQoL, to develop a procedure that allows the design of two models: one from the objective dimension and the other from the subjective dimension of this concept. As main results a model of relations of management indicators, given by local decision makers and another model that relates perception indicators, given by citizens is showed. The comparison between these models makes it possible to generalize that variables such as health, housing and income are determining factors in the UQoL of Cienfuegos's city. [ABSTRACT FROM AUTHOR]

This paper aims to build a set of scenarios for its use in the solution of a stochastic two-stage optimization model for the redesign of the plastics recycling supply chain in Cuba and thus minimize the effect of uncertainty in this strategic decision-making process. The statistical information collected in the characterization of the supply chain is scarce and it is not enough to conform scenarios through the quantitative methods found in the literature. To solve this problem a diffuse inference system is used, which allows the linking of statistical information about the system and the knowledge of experts in recycling and supply chain management in a robust way. This methodology, applied to the plastics recycling in Cuba, makes it possible to increase the number of solutions of the model which, integrated to the twostage solution method, evaluates the solutions to find the most promising ones. A total of nine scenarios are obtained and the optimization of the proposed model is carried out with which a set of 225 solutions is obtained, finding as the best, for all scenarios, the opening of three recycling plants. [ABSTRACT FROM AUTHOR]

Power transmission systems involve an essential relationship in the productive and social sectors of a country. The power transformers are one of the main components in the power systems; these systems allow exporting energy in high voltage over long distances. Failure of a power transformer can lead to a partial or total collapse of an electrical system. There are several procedures for maintenance and diagnosis of such equipment. In this paper, a critical review of eight of the main diagnostic techniques of power transformers is made, including its description and historical evolution, taking into account that currently, those methods can be applied online or those that probably will be applied. [ABSTRACT FROM AUTHOR]

The present work describes a co-rotating shear flexible beam element without shear locking using Timoshenko's beam theories. The co-rotational kinematics is based on the separation of the motion in deformational and rigid body components. The deformation of the beam element is composed of three natural modes of deformation: the extension mode, the symmetric bending mode, and the anti-symmetric bending mode. The respective generalized stresses from these natural modes are self-balanced, allowing the achievement of a consistent tangent stiffness matrix. In this paper, it is detailed and deduced all the algebraic steps for the deduction of the elastic stiffness matrix, the geometric stiffness matrix, and the co-rotation stiffness matrix. Some examples are presented, and the numerical results reveal that the beam element here presented can perform the nonlinear analysis of plane frames and 2D arches. [ABSTRACT FROM AUTHOR]

The shape memory alloys are metals that belong to a class of shape-memory materials. These kinds of materials can memorize their previous form when they are subject to stimuli such as electric, magnetic, and thermic variations. The metal alloys that exhibit this characteristic are commonly named "muscle wires" because their main objective is to generate motion without electric motors or coils. Published studies have demonstrated that, in the case of the muscle wires, their durability and reliability can decrease due a material overheating as a consequence of overcurrent. The design of a buck converter based electric energy supply system for muscle wires is presented in this paper. A control stage based on fuzzy logic is included in the system to regulate the current through the muscle wire. The electrical current adaptation to a maximum magnitude, specified by the muscle wire manufacturer, is achieved in the presence of disturbances, according to the simulation results of the proposed system. [ABSTRACT FROM AUTHOR]

The Hammock(2, 2 ,..., 2/k)-Poset Cover Problem is a variation of the Poset Cover Problem with the same input - set {L1, L2, ..., Lm} of linear orders over the set {1, 2, ..., n}, but the solution is restricted to a set of simple hammock(2, 2 ,..., 2/k) posets. The problem is NP-Hard when k = 3 but is in P when k = 1. The computational complexity of the problem when k = 2 is not yet known. In this paper, we determine the approximation complexity of the cases that have been shown to be NP-Hard. We show that the Hammock(2, 2 ,..., 2/k)-Poset Cover Problem is in APX and, in particular, (1 + 1/2K)-approximable, for k = 3. On the other hand, we also explore the computational complexity for the case where k = 2 [Hammock(2,2)-Poset Cover Problem]. We show that it is in P when the transposition graph of the input set of linear orders is rectangular. [ABSTRACT FROM AUTHOR]

Active learning comprises any process in which students are actively engaged in building understanding of facts, ideas, and skills through instructor-directed tasks and activities undertaken mainly during classes. In this paper we presented results from a comparison of two active learning strategies to teach the agile Scrum framework in the context of an introductory software engineering course. The comparison was carried out through a quasi-experiment in which participants were divided into two groups. The first group used the strategy of active reading on basic concepts of Scrum, while for the other group a game was used; representing two teaching strategies for active learning. The results gave indications at the population level that there are significant differences in the concepts learned by the members of both groups and ratifies the use of active learning strategies to teach Scrum. The results provided empirical evidence indicating that using various active learning strategies facilitates the retention and appropriation of concepts related to Scrum and offer teachers a point of reference about the effectiveness of these two strategies of active learning to teach Scrum concepts. [ABSTRACT FROM AUTHOR]

Risk prevention approaches on activities, functions or processes are fundamental elements to prevent events that are harmful to companies. Each non-conforming product is related to undesirable events associated with the factors intervened in the process. The identification, analysis, evaluation, treatment, communication and monitoring of these unwanted events will help to increase the quality of the products and productivity in the production process. In this paper, we proposed a methodological design for the prevention of risks in production processes. The methodology proposes a novel way of combining statistical quality tools and the ISO 31000 standard for risk management. The validation was performed on a process of packaging of dairy products. The conclusions of this research show that the proposed methodological design is sufficiently flexible to be adapted to any type of manufacturing process that is desired to be monitored and improved. [ABSTRACT FROM AUTHOR]

Developing an effective flow control algorithm to avoid congestion is a hot topic in computer network society. This paper gives a mathematical model for general network at first, and then discrete control theory is proposed as a key tool to design a new flow control algorithm for congestion avoidance in high speed network, the proposed algorithm assures the stability of network system. The simulation results show that the proposed method can adjust the sending rate and queue level in buffer rapidly and effectively. The method is easy to implement and apply to high-speed computer network. [ABSTRACT FROM AUTHOR]

This article designs a new two-dimensional cyclic code that corrects burst errors, also detects and corrects slip errors. One of the characteristic of Class A noise is that it consists of a burst noise which affects several consecutive bits plus a Gaussian noise. This paper proposes a two-dimensional code that allows you to accomplish two tasks one to decrease the burst noise and the other to decrease the synchronization error that occurs when there is a bit slip and the receiver retrieves the information with error. To evaluate performance, a channel with a Class A noise is simulated. The reason signal to noise versus the probability of bit error is plotted, for different two-dimensional cyclic code size and is compared with one-dimensional cyclic code. According to the results obtained this code improves the reliability of the communication system when it is transmitted by a noise-Class A channel, significantly reducing the probability of bit error and slip error. The research is open for the construction of new two-dimensional codes that allow decreasing the probability of burst error and the error of synchronization. [ABSTRACT FROM AUTHOR]

The use of learning management systems (LMS) on educative institutions has been generalized over the last few years, and this is why it is necessary to measure its impact on the pedagogical processes. Aiming to improve the usage of the Moodle platform as a support to the teaching-learning processes, in this paper, the student's perception related to its usage in two subjects is analyzed. For this purpose, the Technological Acceptation Model (TAM) is used. An empiric study over two academic semesters is made, over a 101 students' sample, who were interviewed over the web. The collected information was then used to perform uni-variant and bi-variant statistical analysis and perform a structural equation model. The results obtained reveal a moderately positive attitude towards the employment of the virtual classroom, reflecting a good valorization of its simplicity to use and its utility. At the same time, a good perception of the instructional design applied to virtual classrooms is evidenced, as the students perceive the activities implemented as beneficial to their learning. [ABSTRACT FROM AUTHOR]

Stream processing platforms allow processing and analyzing realtime data. A recognized system for this purpose is the so-called Storm platform, an open-source system for distributed computing, which is a scalable, fast and, fault-tolerant. The Storm platform may be deployed on a large number of processors. However, determining the proper number of processors that are suitable to execute a given Storm based software application is a challenging task, especially if the application is intended to serve a very large user community. One way of solving this is by employing a simulation model that allows the evaluation of its performance under different workload scenarios. In this paper, a simulation model of a Storm application using the DEVS formalism is presented, then, an equivalent model is described using Timed Automata (TA). Throughout a procedure called "Bisimulation", it is checked that both models are effectively equivalent. Finally, the model defined using TA is formally verified evaluating its properties, proving that the simulation model has the same behavior as the real applications. [ABSTRACT FROM AUTHOR]