Tecnura

12-25

Authors: Noé Villegas Flores, Ana Carolina Parapinski Dos Santos

There is a clear agreement that the concept of sustainability has been used to provide the highest level of quality in a product or service where often it is associated with the environment. Although, in certain environments have achieved several standards of sustainability, in the construction sector the solutions are reduced to immediate answers without a significant impact on the social system, economic and environmental. This study has allowed assessing the sustainability of concrete with special characteristics. Two types of concrete have been analyzed, self-compacting and conventional concrete. A tree of requirements has been proposed to support the process of decision maker regarding the index value. Moreover, trends and parameters have been obtained that support the assessment.

37-52

Authors: arlos Fernando Agudelo Rodríguez, Martha Lucía Vaca Bohórquez, César Augusto García Ubaque

The objective of this research was to analyze two social housing construction models that are currently applied in low income families of Bogotá (Habitat social production 'HSP and market models). We built a framework based on housing and habitat concepts according to recent development approaches. We characterized these construction models and designed a methodology, which was applied to analyze processes and results for each case. We concluded that, although HSP model is a variant of market model, the process for giving housing solutions were similar in both cases.

68-81

Authors: César Augusto García Ubaque, María Camila García Vaca, Martha Lucía Vaca Bohórquez

This work discusses the mechanical properties of bricks that were made with clay and sludge mixtures. We analyzed 100:0, 99:1, 95:5, 90:10, 80:20 and 60:40 proportions of clay and sludge. Bricks were cooked between 35 °C to 1100 °C. The sludge used in this study came from sewage treatment plant of G.M. Colmotors Company. These tests were carried out: Water Absorption and mechanical resistance of bricks compression. The results of this study showed that the best percentage of sludge to mix with clay was 5 % to 10 %. Since, this percentage range meets the quality standards of the product demanded in Colombia.

97-108

Authors: Carlos Felipe Urazán Bonells, Adolfo Camilo Torres Prada, Édgar Humberto Sánchez Cotte

The underground pedestrian crossings approach has an infrastructural solution to the current urban mobility. It is based on various criteria such as: the tendency to follow the availability of multifunctional underground spaces of some cities in developed countries, which can reduce the risk of accidents on road at pedestrian crossings, lower construction costs, lower occupancy of public space. Also, the use of underground pedestrian crossing can benefits more the user compared with pedestrian bridge in the following aspects: Protection under negative environmental impacts and reducing more travel distances. As a consequence, this solution would reduce the perception of increased fatigue in the pedestrian using the infrastructure, and would have less negative visual impact. Despite the benefits, the implementation of pedestrian crossings underpass competing with location factors such as the fact of being located near steps at traffic lights, which change the intention of pedestrians on how to cross roads

121-129

Authors: Jesús O. Castaño, Rodrigo Misle Rodríguez, Leonardo Andres Lasso, Adriana Gómez Cabrera, Manuel S. Ocampo

The construction industry in Bogotá (Colombia) has grown steadily in recent years, concentrated between 20 to 30 % of the GDP of the Colombian construction (2012 Camacol), and this has increased the production of waste. As a consequence, some problems have been presented such as the scarcity of raw materials close to the urban center and the depletion of authorized landfill sites. The waste recycling of construction and demolition (RCD) has been a practical pathway to prevent pollution and reduce the impact of the extraction of Virgin aggregates in developed countries. In our country, waste recycling is a novel target that public companies are still working on, along with the management of construction and environment areas. This article discusses the topic of the generation and management of waste generated by the construction in Bogotá, as well as public policies and conditions necessary for the activity of recycling of aggregates. Also, this article presents the viable possibility of waste recycling in our context and drawn conclusions about the opportunities and challenges required to achieve a total management of the RCD.

12-21

Authors: Maximiliano Bueno López, Marco Arteaga Pérez, Antonio Candea Leite

Visual servoing of robot manipulators has been an evolving issue in recent years, especially in applications where the environment is not structured or where access is difficult for operators. To design these controllers, previous simulations are important to adjust parameters or implement a behavioral approach. In this paper we present two different models of vision systems. The models focus on applications in the field of manipulator-robot control. The modeling of video cameras is obtained by using perspective projections. To validate the models, two servo visual controllers in 2D and 3D are simulated

33-40

Authors: Francis Armando Segovia

The research presented in the following paper concerns condensed matter areas in the feld of semiconductor physics. This research uses the basic principles of quantum mechanics, particularly effective mass approximation. The aim of this paper is to determine the energies of ground state as well as the energies of electron-hole transition when a semiconductor heterostructure GaAs-Ga1-xAlxAs is immersed in a barrier of Ga1-yAlyAs, by applying hydrostatic pressure. The methodology proposed in the present work analytically solves Schrodinger's second-order differential equation to find solutions and allow determining the corresponding differential equation together with the energies of transition in the ground state. This is accomplished through the application of hydrostatic pressure. The main results were obtained using software package Mathematica 5.0. Results indicate a regime of strong confinement for small widths of the potential well in semiconductor heterostructures, where the confinement potential lessens with pressure for the charge-carrier function (electron-hole). However, the findings demonstrate that, in the regime of weak confinement, the effects of hydrostatic pressure on the heights of the barrier are more significant, and there is also a reduction in carrier energies.

53-63

Authors: Danilo Alfonso López Sarmiento, Carlos Andrés Martínez Alayón, Edward Johannes Uribe Sierra, Nicolas Carlos Eduardo Torres Vallejo

This paper presents the results obtained by representing losses in a digital video transmission using ARIMA and SARIMA models. The experiments were conducted following the Box-Jenkins methodology and using programming language R for the estimation of coefficients. A comparison of these two models was conducted in order to determine what the most appropriate model was in order to represent the original series and estimate future values. The findings indicate that SARIMA provide better matching and better prediction of the original data set.

74-83

Authors: Nancy Esperanza Olarte López, Astrid Rubiano Fonseca

This paper shows the design and implementation of a storage system with security parameters intended for biological signals. The system deals with two important aspects. On the one hand, signal processing; on the other hand, software application developments that support telemedicine platforms. The rationale behind the implementation of such systems is the current situations in hospital environments, where there is the need to transmit these signals remotely with the best possible quality so as to provide an effective specialist diagnosis in the shortest time possible. First, within this methodology, ECG conditioning signal was proposed; then, temperature signal processing was also proposed. Additionally, the project considers respiration waveforms, and blood pressure signals are also processed. Different calculations were proposed for signal processing in order to implement circuits with discrete and surface electronic components. The implemented software was created using the Java platform, including security authentication parameters based on specific knowledge (username, password and a secret question answer). This allowed subsequent visualization of several ECG and temperature signals associated with patients. The information captured is centrally stored and managed at the Military University Telemedicine Research Group - TIGUM server – where the whole project was developed. Additionally, the final prototype allows including more protocols, communication technologies for data transmission and reception, as well as security parameters for future implementation.

99-108

Authors: Carlos Alfonso Zafra Mejía, Nancy Ángela Peña Valbuena, Santiago Álvarez Prieto

Road sediments accumulated in dry weather carry metallic elements, which affects water resources when transported by runoff and deteriorates the air quality when suspended by wind and the turbulence induced by traffic. This paper presents the results of a pollution assessment on heavy metal particles associated to road sediment from two particular areas (i.e. Zones 1 and 2) of the Bogotá-Soacha highway (Colombia). Road sediment was collected in each area by direct sweep over a surface of 0.25 m2 and for a period of four months. The concentration of Mn, Fe, Cu, Zn, As, Cd, Ba and Pb was determined per size fraction (less than 250 !m from road sediment). These figures were obtained by means of fame atomic absorption spectrometry and also by using inductively coupled plasma mass spectrometry. The results suggest that the main origin of heavy metals were the mobile sources (i.e. the wear of tires, brake pads and automotive parts). In addition, it is shown that the concentration of Pb and Zn was higher than that allowed by current regulations (used as reference). With regard to urban soils, heavy metals that exceeded the permissible limits were as follows: Pb (21.7 % and 87.0 % of the time in Zones 1 and 2, respectively) and Zn (84.8 % and 82.6 % of the time in Zones 1 and 2, respectively).

121-137

Authors: Fredy Hernán Martínez Sarmiento, Alberto Delgado

Many of the "intelligent" features that we want in robots, machines and man-made systems, are already well implemented by nature. Therefore, it is reasonable to expect that, by imitating nature, "intelligent solutions" to human problems can be found. In this paper, we present a survey on the analysis of current developments connected to artificial design inspired by nature. Particular interest is devoted to living organisms. The study takes the POE model as the starting point, establishing a three-dimensional framework with three axes of biological development, namely phylogenetic, ontogenetic and epigenetic axes. For each of these axes, a survey of existing hardware implementations is conducted in order to gather their characteristics, strengths and weaknesses and establish a general map of the latest technological developments. Finally, we conclude that implementing this type of nature inspired algorithms is not only important but also indispensable in solving many complex problems today.

153-166

Authors: Fabián Andrés Giraldo, Elizabeth León, Jonatan Gómez

This paper presents introductory materials to datastream mining processes using clustering techniques. The limitations of traditional techniques are observed and the various approaches found in the literature are explained. The major trends in the different algorithms indicate that most applications separate the process into two phases; namely an online phase, which makes a data stream summarization in addition to the application of decay functions regardless of the data, and an offine phase, which is the application of traditional clustering techniques in order to obtain the cluster requested by users. The net result of this paper is a selection of desirable characteristics of an algorithm, based on the theoretical underpinnings of each of the works analyzed.

177-190

Authors: Nelson Flórez Ramírez, Francisco Javier López Correa, Andrea Lucia Flórez Rendón

Productivity and quality have been important in the search for higher levels of competitiveness in organizations. This, together with technological development, has allowed organizations to grow. However, low technological development in manufacturing industries (especially bakeries) has led to low levels of competitiveness in Colombia. "Politécnico Colombiano JIC" implemented a project called "Design and development of a piece of equipment for Quality Control in the breadmaking industry" (also strengthening the bonds between "universities and the industry") in order to implement and socialize technological knowledge for the growth of SMEs. The project was aimed at standardizing and improving the quality levels of fermentation processes (which are critical in bread making). Once data was collected, the product was assessed during and after the process of fermentation. Process conditions were tested together with the variables of greatest incidence in fermentation, namely temperature and humidity. Statistical analysis and quality tests showed the need for standardization in terms of process design, product specifications and quality characteristics of the product to be manufacture (e.g. length, width and height). The results from initial analysis allowed identifying potential specifications as well as obtaining the parameters of a mechanism for controlling process variables. To accomplish this, pictures of sample products into the fermentation tunnel (where the process takes place while maintaining the required conditions) were taken using a linear scanner. By avoiding the handling of the product, bread fermentation time was reduced by 50%. The mechanism allows making accurate measurements and recording data by preventing alterations in the process conditions for critical variables, which contributes to high-quality manufacture

10-20

Authors: Luis F. Pedraza, Andrea Cepeda Ruiz, Dora Ballesteros

The present paper illustrates the process of fully deploying a wireless network for the local community at Ciudad Bolívar (Bolivar wireless), an outer-city area with the highest povertyd levels in Bogotá (Colombia). This paper shows implementation procedures and design stages for the nodes of the community wireless network. A mesh-based network topology and various Information and Communication Technology (ICT) applications are utilized. These applications are currently being used by the local community due to the service coverage now provided by the community wireless nodes. The performance of the nodes is evaluated and recommendations are provided. Conclusions are drawn in the final part of the paper.

41-49

Authors: Carlos David Zuluaga Ríos, Eduardo Giraldo

This paper presents a methodology for designing a minimum variance control- (MVC) and Kalman filter- (KF) based adaptive system. MVC is a technique of great interest, and it is widely used because it can reduce either energy or material consumption, or else, it can increase production performance. The Kalman filter is a recursive method that provides stochastic support for adaptive systems, showing feasibility and good results for dynamic system identification. The methodology implementation was conducted in a multiplatform integrated development environment called Qt Creator Qt 4.7-based, yielding good results when applied to the reference tracking problem. Moreover, it can be observed that the adaptive control scheme exhibits good settling times and notoriously appropriate overshoots.

61-71

Authors: Víctor Rogelio Tirado Picado

This paper reports the activities associated to determining the maximum flow rate of sanitary sewer pipes (either concrete or PVC) in urban areas of the city of Managua. There is a particular interest in gathering data about how to determine the maximum flow rate of sanitary sewage. The climate is studied together with general population data from the city of Managua, as well as from other neighborhoods where the study is conducted. Subsequently, the performance of collecting water in the sanitary sewage networks selected is weighted, and then a mathematical method to obtain the maximum flow rate is applied. Finally, a procedure for determining the flow coefficient is proposed for domestic sewage

87-95

Authors: Ilber Adonayt Ruge Ruge, José David Alvarado

This paper presents the use of Field Programmable Oate Arrays (FPOA) to evaluate an Artifcial Neural Network (ANN) system, and also to apply image pattern recognition to alphabetic characters in contexts where different neural network models are utilized. This is performed in order to evaluate the performance of the neural networks implemented in the FPOA and also to analyze the Spartan-3 FPGA XCS200 performance. This study has four phases: neural network model selection; development of a training platform using Labview RNA; design, implementation and verification of RNA models; and parameter setup to evaluate RNA Spartan-3 FPOA XCS200 performance.

111-128

Authors: Carlos A. Castillo Medina, Felipe Forero Rodríguez

The present paper attempts to survey the current state of the network protocol called IPv6; starting from the evolution of IPv4 (which motivated the design of new features) to the details that are comprised in the new version of the Internet Protocol. The main sections explain the drawbacks of IPv4 that can be overcome by implementing IPv6, highlighting aspects such as security, mobility, and Quality of Service (QoS).

12-25

Authors: José Alexander Martínez, Fredy Hernán Martínez S

We propose a data-analysis-based methodology for maintaining trees that affect power distribution networks. From the information captured in the field, we use fuzzy-logic-based techniques and models together with genetic algorithms so as to focus maintenance activities on the optimal time and place. The strategy is aimed at two key aspects: first, the history of failure events caused by trees on medium-voltage power supply systems; this information is used to calculate quality indicators such as energy-not-supplied (ENS) and number-of-users (NU) affected due to falling trees only. In this case we use a fuzzy-logic-based system to weight and find the critical circuits on which forest maintenance should be performed. Second, we construct an objective function based on tree-to-network distances and growth patterns of trees (classifed per species) in order to simulate forest maintenance; this is achieved using a genetic algorithm to determine optimum pruning cycles for a given power supply system. We use real historical data of medium voltage circuits for system setting as well as for performance evaluation.

38-46

Authors: Diego Mauricio Camargo Casas

This paper presents a pre-coding technique, known as "Dirty Paper Coding", which allows transmission with limited levels of power over channels where the interference level is known by the transmitter. The interference levels considered have finite variance-just like in MIMO (multiple-input and multiple-output) communications, where there is ISI (inter-symbol interference), Intra-Cell and Inter-Cell interference among other types of interference. The role of proper scaling parameters at the transmitter and receiver is described. Such parameters make use of a linear estimator that minimizes the mean square error of the signals involved. Moreover, a quantization scheme equivalent to a module operation is explained in detail. The purpose of this scheme is to pre-cancel the interference at the transmitter, showing that interference knowledge is used by the encoder as much as possible, namely the encoder attempts to adapt itself to the interference value. Thus, it is possible to decode the signal to make it look almost like the original signal since the new signal is now totally independent of interference.

55-62

Authors: Edgar Alirio Aguirre, Luis F. Pedraza, Gabriel A. Puerta A

This paper presents an evaluation of the WCETT (Weighted Cumulative Expected Transmission Time) routing metric setup for a cognitive radio network. This metric setup is based on the software application called CRCN (Cognitive Radio Cognitive Network Simulator), which runs over the simulation environment called NS2 (Network Simulator 2). Comparative experiments to assess throughput values were conducted for the following protocols: MAC802.11, MACCON, MACN, Simple and TDMA

77-89

Authors: Sandra Ximena Carvajal Quintero, Juan David Marín Jiménez

Distributed Generation (DG) has emerged as an important alternative to provide electrical energy since it could increase the reliability and security of electric power supply in the short, medium and long term. Despite these potential advantages, the Colombian regulatory framework does not recognize DG as a valid activity within the country's interconnected system and, as such, no policy exists to encourage investment in small-scale generation projects. This article first describes the technical and financial aspects of DG, and then analyses regulatory proposals regarding the inclusion of DG in power systems outside Colombia. These aspects are then brought together in a mental model based on the concepts of feedback theories as well as of cause and effect relationships; such concepts are part of the System Dynamics methodology (SD). This model is aimed at creating a virtual world which would allow the usefulness of various regulatory alternatives to be evaluated and thus an appropriate option to be chosen according to the regulation that best fits technical, climactic and economic conditions, and also according to the market structure used in the Colombian interconnected system.

107-115

Authors: Duvan Cardona, Danilo López, Cesar A. Hernández

This investigation work shows the way to implement the rapidly transformed of Fourier using the algorithms of Cooley-Tukey, applied to the analysis and calculation of the harmonic distortion in homes and small businesses that it's don't knows the energy's quality that is delivered daily. The investigation is based on a diferent parts of hardware necesary for the recmicrocontroller architecture for good perfoman-koning of the FFT of 1024 points and the reckoce whit a high level language, olso develop the ning of THD level.