Search

Nowadays utilization of obsolete products (UOP) in manufacturing paper, has taken a great interest both in terms of business and research. This phenomenon has been due to environmental awareness is being structured in such companies, and also to advancement in supply chain management. For a correct collection of UOP, It must design a reverse supply chain that is able to properly administer or manage the collection of these products, with a low cost. In supply chain design will have in consideration all components required for paper collection, such as recovery center location, taking necessary information about three paper manufacturing plants and recycling centers located in the middle zone of Valle del Cauca. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The energy transition relies on the integration of non-conventional renewable energy sources. These disruptive technological developments alter the functioning and operation of the electric power system. This paper examines the impacts of wind power on transient stability indicators of the power system, using an implicit formulation and the nine-bus test system. The research findings indicate that transient stability indicators are sensitive to the location and duration of faults. Furthermore, there is an observed trend of increasing maximum rotor speed deviation and oscillation duration, indicating reduced stability margins. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The supply of growing electricity demand is possible through continuous technological advances and the expansion of national and international electrical systems. This scenario could introduce voltage drops and consequent changes in the reactive power flow throughout the electrical network. In order to control these problems, various strategies have been developed as a solution to improve the transport and distribution of electrical energy. One of them is the Flexible Alternating Current Transmission System (FACTS), and more specifically the STATic synchronous COMpensator (STATCOM). This paper investigates the influence and effectiveness of STATCOM to mitigate the losses in the transmission lines and its impacts on bus voltage drops. The simulations are performed using the software DIgSILENT PowerFactory and the results showed that STATCOM reduces the power system losses in an interval of 23.86% until 32.86%, and in addition, the STATCOM decreases the annual energy cost by 7.82% in the implemented test case. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Software process standards such as the ISO/IEC 29110 have been implemented by Very Small Entities (VSE) in order to develop quality software and achieve improvements in terms of time, budget, documentation, and other subjects. The generic profile group established in such a standard includes a set of profiles with situational factors of occurrence applicable to some VSEs. However, documented case studies of the ISO/IEC 29110 implementation in Latin America companies are limited, causing uncertainty about the viability of such a standard in VSEs established in the region. Different conditions of each environment—company type, size, country, etc.—can influence the implementation of a software project. Such a fact can affect the possibility of quality improvement by using the standard. In this paper we implement the project management process included in the basic profile of the ISO/IEC 29110 in an automotive Ecuadorian company. We identified extra effort—17.30%—and overruns—17.06%—triggered by implementing the project management process in this exercise are within the parameters defined and evaluated in previous literature. Besides, we summarize a set of lessons learned acquired during such an implementation. Finally, the findings of this study will allow VSEs to decide whether is convenient to implement this standard in such an environment. [ABSTRACT FROM AUTHOR]

The search for technological alternatives to satisfy diverse global needs has triggered an arduous process of research and technological developments worldwide for the use of renewable resources. For their part, linear parabolic trough collectors have proven to be an alternative for the water heating process and for the production of electric energy. For its part, the research group in energy systems, automation and control (GISEAC) of the Technological Units of Santander, developed a prototype parabolic trough collector with low-cost materials available in the region (Bucaramanga, Colombia). Consequently, in order to improve the performance of the device, this paper presents the sizing, implementation and testing of a single-axis solar trajectory tracking system in a small-scale parabolic trough collector, applying a closed-loop control system. The control system is governed by a system integrated by an ESP32 module and a Raspberry PI3 microcontroller. The axis of the device is coupled to a mechanism composed of a gear and chain transmission system, directly coupled to an electric motor. The positioning of the collector angle is determined by a sensor that directly measures the amount of LUX and identifies by means of the developed algorithm, the location with the highest levels of direct incident solar radiation. In this way, the system can track the solar position throughout the course of the solar day. Finally, it should be noted that the maximum percentage of deviation of the solar tracking system is less than 1%. At the same time, the performance of the implemented solar trajectory tracking system “Automatic solar tracking system” increased by more than 40% with respect to the initial tracking system “Manual solar tracking system”. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electromyography is a test widely used in the study of the electrical activity of muscles and nerves usually for medical purposes to measure the health of muscles and nerves in patients, however, the similarity of the signals generated in this study with those used in robotics in control systems, has opened the possibility of using them to bio-medical applications. This paper article presents a prototype for the control of a palletiser with one degree of freedom through EMG signals, the prototype was designed by digital electronics and allows the control of the palletiser in real time. The design is modular and consists of the following modules: acquisition and filtering; Processing and digital electronic decision system and, finally, the control-power interface that allows Human-machine interaction in a friendly way. The filtering and processing of EMG signals reduces the experimental noise by allowing a pattern to be established in the power signals. It achieves a robust control system that operates in real time by the effective value of power and in addition, the Human machine interface helps in the interpretation of control variables. Finally, the incorporation of reliable and efficient control systems based on EMG signals and digital electronics, allows exploring a viable alternative for the development of bio-medical and robotics prototypes such as the control of robotic arms in real time. [ABSTRACT FROM AUTHOR]

This paper presents a methodology for protection coordination in microgrids that considers account non-standard features of directional over-current relays (OCRs). In the proposed approach three decision variables are considered for each relay; namely, the standard characteristic curve (SCC), Time Multiplier Setting (TMS) and maximum limit of the plug setting multiplier (PSM). The proposed mixed integer non-linear programing model is solved by means of a specialized genetic algorithm (GA) implemented in Matlab. Several tests were performed on a modified version of the IEEE-30 bus test system considering on-grid and off-grid operational modes. The results evidenced the robustness and applicability of the proposed approach in real-size microgrids that host distributed generation and exhibit several operational modes or topologies. [ABSTRACT FROM AUTHOR]

In terms of sustainability of tourist beaches, an impact factor is the measurement of parameters associated with ecosystem quality, sanitary quality and recreational quality. The measurement allows to identify the deterioration and the virtues of this type of beaches to make correct decisions about coast management. The paper presents the conditions and technical specifications of system monitoring for the beaches of Santa Marta city. The solution includes the sensor nodes, sink node, monitoring center, the mesh wireless sensor network and the radio links to interconnect the five beaches. To make the system viable, it was prototyped and tested. The distance between nodes of the mesh was determined on based in the measurements of received signal strength and lost packets, the modelling of the path loss and shadowing in wireless channel. The characteristics of radio links was established using the digital topography of the terrain and the Longley-Rice model. An average wireless channel attenuation of - 42.46 dB, path-loss exponent of 2.08, Shadowing of 5.6 dB for beaches and distance between nodes is 130 meters were obtained. Additionally, seven radio links were parameterized for circumvent the hills of the Sierra Nevada de Santa Marta. For a triangular mesh and the selected devices, the tests gave 99.2% reliability. The results obtained support the implementation of the proposal. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

These instructions give you guidelines for preparing papers for IEEE Transactions and Journals. Use this document as a template if you are using Microsoft Word 6.0 or later. Otherwise, use this document as an instruction set. Paper titles should be written in uppercase and lowercase letters, not all uppercase. Avoid writing long formulas with subscripts in the title; short formulas that identify the elements are fine (e.g., "Nd-Fe-B"). Do not write "(Invited)" in the title. Full names of authors are preferred in the author field, but are not required. Put a space between authors' initials. The abstract must be a concise yet comprehensive reflection of what is in your article. In particular, the abstract must be self-contained, without abbreviations, footnotes, or references. It should be a microcosm of the full article. The abstract must be between 150-250 words. Be sure that you adhere to these limits; otherwise, you will need to edit your abstract accordingly. The abstract must be written as one paragraph, and should not contain displayed mathematical equations or tabular material. The abstract should include three or four different keywords or phrases, as this will help readers to find it. It is important to avoid over-repetition of such phrases as this can result in a page being rejected by search engines. Ensure that your abstract reads well and is grammatically correct. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This document presents in detail the mathematical formulation of the second renewable energy auction in Colombia, used for the allocation of long-term energy contracts, which was carried out through a double-sided auction, defined in Resolutions 4-0590 and 4-0591 of 2019 from the UPME. The mixed integer linear programming model developed in this paper solves an optimization problem that seeks the combination of offers that maximizes the benefit of the consumer, subject to operational and economic constraints proposed by regulatory mechanisms. The effectiveness of the algorithm developed in Python was tested by validating it with real data, obtaining the same results published by UPME. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper shows the characterization of the matter and radiation transfer functions. The transfer functions provide information about behavior of every species perturbation during radiation epoch, which allows to determine the evolution of these species during matter epoch. Graphics of the radiation and matter transfer functions, using the software CAMB are presented, in order to explain how large structures were formed. [ABSTRACT FROM AUTHOR]

The Unified Process (UP) is a processes framework widely known and used by the software industry and academic community. UP was developed under the conception of a universal application, but even a single process is not appropriate to address all development projects since optimal process depends on the particularities of each project or organization. Frequently, many process components need to be adapted to the organization or project needs, a complex task because the experience and knowledge required. Perform adaptation in an inappropriate way is prone to error due to the difficulties for taking tailoring decisions. The paper goal is proposing a canonical software processes family based on the Unified Process to support software process tailoring. Our methodology was based on the meta-process CASPER to build a software process family and we use the Case Study method as a strategy for validating the canonical process family empirically. As a result, we show a canonical software processes family, which will serve as a platform for determining a process family based on Unified process in a small software organization. This canonical family has the advantage that uses a tailoring mechanism following a transformation strategy that encapsulates tailoring decisions in order to systematize this activity. In this work, we show the initial results in the applicability of a canonical software process family as base in the building the software process families based on UP in the small companies context, and also we conclude that the UP is a process framework with spread spectrum, which limited its formulation like a general software process family, due to that a process family requires determining carefully the application domain known as software process family scope. [ABSTRACT FROM AUTHOR]

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientia et Technica is the property of Scientia et Technica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)