Showing papers by "Instituto Tecnológico Autónomo de México published in 2017"

Application of load monitoring in appliances’ energy management – A review

Abstract: Energy monitoring is one of the important aspects of the energy management, as such there is a need to monitor the power consumption of a premises before planning some of the technical measures to minimize the energy consumption. This paper presents the current state of art of appliances’ energy management through Intrusive Load Monitoring (ILM) and Non-intrusive Load Monitoring (NILM), ILM is referred to as distributive sensing and NILM is based on single point sensing. In an effort to explore the recent trend in Energy Management for researchers in the area, various techniques of Home Energy Management (HEM) using ILM and NILM have been analyzed and categorized. Different contributions made by the researchers have been highlighted together with some techniques of reducing power consumption of a building for cost saving and greener environment. This study reveal that there are issues concerning load monitoring and load management that need the attention; issues such as more accurate recognition and the need for monitoring system that can recognize as many kind of loads as possible. More efforts to apply NILM in appliances’ energy management is also required. Finally there is need for promoting the energy management culture among the electricity consumers whether in homes, offices or industries. The study will help the researchers in the area to have a clear vision of the recent trends in the area.

Non-invasive fetal monitoring: a maternal surface ECG electrode placement-based novel approach for optimization of adaptive filter control parameters using the LMS and RLS algorithms

Abstract: This paper is focused on the design, implementation and verification of a novel method for the optimization of the control parameters (such as step size μ and filter order N) of LMS and RLS adaptive filters used for noninvasive fetal monitoring. The optimization algorithm is driven by considering the ECG electrode positions on the maternal body surface in improving the performance of these adaptive filters. The main criterion for optimal parameter selection was the Signal-to-Noise Ratio (SNR). We conducted experiments using signals supplied by the latest version of our LabVIEW-Based Multi-Channel Non-Invasive Abdominal Maternal-Fetal Electrocardiogram Signal Generator, which provides the flexibility and capability of modeling the principal distribution of maternal/fetal ECGs in the human body. Our novel algorithm enabled us to find the optimal settings of the adaptive filters based on maternal surface ECG electrode placements. The experimental results further confirmed the theoretical assumption that the optimal settings of these adaptive filters are dependent on the ECG electrode positions on the maternal body, and therefore, we were able to achieve far better results than without the use of optimization. These improvements in turn could lead to a more accurate detection of fetal hypoxia. Consequently, our approach could offer the potential to be used in clinical practice to establish recommendations for standard electrode placement and find the optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing. Ultimately, diagnostic-grade fetal ECG signals would ensure the reliable detection of fetal hypoxia.

Robust IDA‐PBC for underactuated mechanical systems subject to matched disturbances

Abstract: The problem of robustification of interconnection and damping assignment passivity-based control for underactuated mechanical system vis-a-vis matched, constant, and unknown disturbances is addressed in the paper. This is achieved adding an outer-loop controller to the interconnection and damping assignment passivity-based control. Three designs are proposed, with the first one being a simple nonlinear PI, while the second and the third ones are nonlinear PIDs. While all controllers ensure stability of the desired equilibrium in spite of the presence of the disturbances, the inclusion of the derivative term allows us to inject further damping enlarging the class of systems for which asymptotic stability is ensured. Numerical simulations of the Acrobot system and experimental results on the disk-on-disk system illustrate the performance of the proposed controller. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Short and Long Run Uncertainty

Abstract: Uncertainty appears to have both a short-run and a long-run component, which we measure using firm and macro implied volatility data from 30 days to 10 years duration. Examining a panel of over 4,000 firms from 1996 to 2013 we find that investment is significantly more sensitive to long-run uncertainty, while employment responds equally to short- and long-run uncertainty. We build a model to investigate this phenomenon, and find that the higher adjustment costs and lower depreciation rates of capital can explain why investment is particularly sensitive to longer-run uncertainty. This suggests that investment in other long-lived and irreversible capital goods - like buildings and intangibles such as R&D and organizational capital - will also be particularly sensitive to long-run uncertainty. We then examine drivers of uncertainty over different time horizons, finding oil price volatility is particularly important for short-run uncertainty, policy uncertainty is particularly important for long-run uncertainty, while currency volatility and CEO turnover appear to equally impact short and long run uncertainty.

Task Conflict and Employee Creativity: The Critical Roles of Learning Orientation and Goal Congruence

Abstract: We add to human resource literature by investigating how the contribution of task conflict to employee creativity depends on employees’ learning orientation and their goal congruence with organizational peers. We postulate a positive relationship between task conflict and employee creativity and predict that this relationship is augmented by learning orientation but attenuated by goal congruence. We also argue that the mitigating effect of goal congruence is more salient among employees who exhibit a low learning orientation. Our results, captured from employees and their supervisors in a large, Mexican-based organization, confirm these hypotheses. The findings have important implications for human resource managers who seek to foster creativity among employees. © 2015 Wiley Periodicals, Inc.

Trajectory tracking passivity-based control for marine vehicles subject to disturbances

Abstract: In this paper we present a dynamic model of marine vehicles in both body-fixed and inertial momentum coordinates using port-Hamiltonian framework. The dynamics in body-fixed coordinates have a particular structure of the mass matrix that allows the application of passivity-based control design developed for robust energy shaping stabilisation of mechanical systems described in terms of generalised coordinates. As an example of application, we follow this methodology to design a passivity-based controller with integral action for fully actuated vehicles in six degrees of freedom that tracks time-varying references and rejects disturbances. We illustrate the performance of this controller in a simulation example of an open-frame unmanned underwater vehicle subject to both constant and time-varying disturbances. We also describe a momentum transformation that allows an alternative model representation of marine craft dynamics that resembles general port-Hamiltonian mechanical systems with a coordinate dependent mass matrix.

Different variants of R13 moment equations applied to the shock-wave structure

Abstract: Various versions of the regularized 13-moment system (R13) are applied to the problem of the shock wave structure in a monatomic Maxwell gas for Mach numbers up to M = 10. Numerical solutions are compared to direct simulation Monte Carlo results computed by the SMILE++ software system, in order to identify applicability and limitations of the variants. Over time, several versions of the R13 equations were presented, which differ in non-linear contributions for high-order moments but agree in asymptotic expansion to the third order in the Knudsen number. All variants describe typical subsonic microflows well, for which the non-linear contributions only play a minor role. The challenge of the present study is to determine the real boundaries of applicability of each variant of the moment equations as applied to non-equilibrium supersonic flows, depending on the Mach number and local Knudsen number.

Impact on yard efficiency of a truck appointment system for a port terminal

Abstract: Port terminals consist of two interfaces for transferring cargo among transport modes: (1) the seaside or quayside interface and (2) the landside interface. At the seaside interface, cargo is loaded and unloaded from the vessels and stored temporarily at the yard. Landside operations consist of receiving and dispatching cargo from external trucks and rail. The increasing volumes of international trade are demanding more efficient cargo handling throughout the port logistic chain and coordination with the hinterland, hence attracting more attention from both practitioners and researchers on the landside interface of ports. Due to the high variability of truck arrivals with a significant concentration at peak hours, congestion at the access gates of ports and an unbalanced utilization of the resources occur. Truck appointment systems (TAS) have already been implemented in some ports as a coordination mechanism to reduce congestion at ports, balance demand and capacity, and reduce truck turnaround times. Based on the current situation faced by the Port of Arica, Chile, this paper aims to analyze potential configurations of a TAS and evaluate its impacts on yard operations, specifically in the reduction of container rehandles, as well as truck turnaround times. For this, a discrete-event simulation model and a heuristic procedure are proposed and experimentation is performed using historical data from the port terminal. Results indicate that implementing a TAS may significantly benefit yard operations in terms of reducing container rehandles as well as truck waiting times.

Consolidation of renders and plasters

Abstract: The paper addresses the consolidation of plasters and renders showing loss of cohesion, with the use of a treatment with a liquid consolidating product aiming to reach a depth of several mm up to several cm. The main aim of the paper is offering a guideline on how to choose a consolidant, suitable and compatible for the mortar type and its condition, and how to assess the performance of a consolidation treatment.

Is Abdominal Fetal Electrocardiography an Alternative to Doppler Ultrasound for FHR Variability Evaluation

Abstract: Great expectations are connected with application of indirect fetal electrocardiography (FECG), especially for home telemonitoring of pregnancy Evaluation of fetal heart rate (FHR) variability, when determined from FECG, uses the same criteria as for FHR signal acquired classically – through ultrasound Doppler method (US) Therefore, the equivalence of those two methods has to be confirmed, both in terms of recognizing classical FHR patterns: baseline, accelerations/decelerations (A/D), long-term variability (LTV), as well as evaluating the FHR variability with beat-to-beat accuracy – short-term variability (STV) The research material consisted of recordings collected from 60 patients in physiological and complicated pregnancy The FHR signals of at least 30 minutes duration were acquired dually, using two systems for fetal and maternal monitoring, based on US and FECG methods Recordings were retrospectively divided into normal (41) and abnormal (19) fetal outcome The complex process of data synchronization and validation was performed Obtained low level of the signal loss (45% for US and 18% for FECG method) enabled to perform both direct comparison of FHR signals, as well as indirect one – by using clinically relevant parameters Direct comparison showed that there is no measurement bias between the acquisition methods, whereas the mean absolute difference, important for both visual and computer-aided signal analysis, was equal to 12 bpm Such low differences do not affect the visual assessment of the FHR signal However, in the indirect comparison the inconsistencies of several percent were noted This mainly affects the acceleration (78%) and particularly deceleration (54%) patterns In the signals acquired using the electrocardiography the obtained STV and LTV indices have shown significant overestimation by 10% and 50% respectively It also turned out, that ability of clinical parameters to distinguish between normal and abnormal groups do not depend on the acquisition method The obtained results prove that the abdominal FECG, considered as an alternative to the ultrasound approach, does not change the interpretation of the FHR signal, which was confirmed during both visual assessment and automated analysis

Job Satisfaction and Innovative Performance in Young Spanish Employees: Testing New Patterns in the Happy-Productive Worker Thesis—A Discriminant Study

Abstract: We aimed to make a theoretical contribution to the happy-productive worker thesis by expanding the study to cases where this thesis does not fit. We hypothesized and corroborated the existence of four relations between job satisfaction and innovative performance: (a) unhappy-unproductive, (b) unhappy-productive, (c) happy-unproductive, and (d) happy-productive. We also aimed to contribute to the happy-productive worker thesis by studying some conditions that influence and differentiate among the four patterns. Hypotheses were tested in a sample of 513 young employees representative of Spain. Cluster analysis and discriminant analysis were performed. We identified the four patterns. Almost 15 % of the employees had a pattern largely ignored by previous studies (e.g., unhappy-productive). As hypothesized, to promote well-being and performance among young employees, it is necessary to fulfill the psychological contract, encourage initiative, and promote job self-efficacy. We also confirmed that over-qualification characterizes the unhappy-productive pattern, but we failed to confirm that high job self-efficacy characterizes the happy-productive pattern. The results show the relevance of personal and organizational factors in studying the well-being-performance link in young employees.

Large-Scale Affirmative Action in School Choice: Admissions to IITs in India

Abstract: We provide a real-life application of a large scale affirmative action policy in school choice in the context of engineering school admissions in India where students not only care about what program they are matched to but also what type of seat category they are admitted under. We explain the market and the mechanism currently in use. Two significant shortcomings of the current mechanism are explained. The affirmative action policy in use leaves many seats vacant even though there are students who would take these seats. We provide the insight of a potential matching-theoretical solution to these problems.

To shape or to be shaped: engaging stakeholders in fishery management advice

Abstract: The purpose of this paper is to assess the effectiveness of the collaboration between stakeholders and scientists in the construction of a bio-economic model to simulate management strategies for the fisheries in Iberian Atlantic waters. For three years, different stakeholders were involved in a model development study, participating in meetings, surveys and workshops. Participatory modelling involved the definition of objectives and priorities of stakeholders, a qualitative evaluation and validation of the model for use by decision-makers, and an iterative process with the fishing sector to interpret results and introduce new scenarios for numerical simulation. The results showed that the objectives of the participating stakeholders differed. Incorporating objectives into the design of the model and prioritising them was a challenging task. We showed that the parameterization of the model and the analysis of the scenarios results could be improved by the fishers’ input: e.g. ray and skate stocks were explicitly included in the model; and the behaviour of fleet dynamics proved much more complex than assumed in any traditional modelling approach. Overall, this study demonstrated that stakeholder engagement through dialogue and many interactions was beneficial for both, scientists and the fishing industry. The researchers obtained a final refined model and the fishing industry benefited for participating in a process, which enables them to influence decisions that may affect them directly (to shape) whereas non-participatory processes lead to management strategies being imposed on stakeholders (to be shaped).

The Usefulness of Tenacity in Spurring Problem-Focused Voice: The Moderating Roles of Workplace Adversity

Abstract: Drawing from conservation of resources theory and affective events theory, this article examines the hitherto unexplored relationship between employees’ tenacity levels and problem-focused voice behavior, as well as how this relationship may be augmented when employees encounter adversity in relationships with peers or in the organizational climate in general. The study draws on quantitative data collected through a survey administered to employees and their supervisors in a large manufacturing organization. Tenacity increases the likelihood of speaking up about problem areas, and this relationship is strongest when peer relationships are characterized by low levels of goal congruence and trust (relational adversity) or when the organization does not support change (organizational adversity). The augmenting effect of organizational adversity on the usefulness of tenacity is particularly salient when it combines with high relational adversity, which underscores the critical role of tenacity for spurring problem-focused voice behavior when employees negatively appraise different facets of their work environment simultaneously. The results inform organizations that the allocation of personal energy to reporting organizational problems is perceived as particularly useful by employees when they encounter significant adversity in their work environments. This study extends research on voice behavior by providing a better understanding of the likelihood that employees speak up about problem areas, according to their levels of tenacity, and explicating when this influence of tenacity tends to be more prominent.

Equity Volatility Term Structures and the Cross Section of Option Returns

Abstract: The slope of the implied volatility term structure is positively related to future option returns. I rank firms based on the slope of the volatility term structure and analyze the returns for straddle portfolios. Straddle portfolios with high slopes of the volatility term structure outperform straddle portfolios with low slopes by an economically and statistically significant amount. The results are robust to different empirical setups and are not explained by traditional factors, higher-order option factors, or jump risk.

Symmetric Liapunov center theorem

Abstract: In this article, using an infinite-dimensional equivariant Conley index, we prove a generalization of the profitable Liapunov center theorem for symmetric potentials. Consider a system $$(*)\; \ddot{q}= - abla U(q)$$ , where U(q) is a $$\Gamma $$ -invariant potential and $$\Gamma $$ is a compact Lie group acting linearly on $${\mathbb {R}}^n$$ . If system $$(*)$$ possess a non-degenerate orbit of stationary solutions $$\Gamma (q_0)$$ with trivial isotropy group, such that there exists at least one positive eigenvalue of the Hessian $$ abla ^2 U(q_0)$$ , then in any neighborhood of $$\Gamma (q_0)$$ there is a non-stationary periodic orbit of solutions of system $$(*)$$ .

Tacit to explicit knowledge conversion

Abstract: The ability to create, use and transfer knowledge may allow the creation or improvement of new products or services. But knowledge is often tacit: It lives in the minds of individuals, and therefore, it is difficult to transfer it to another person by means of the written word or verbal expression. This paper addresses this important problem by introducing a methodology, consisting of a four-step process that facilitates tacit to explicit knowledge conversion. The methodology utilizes conceptual modeling, thus enabling understanding and reasoning through visual knowledge representation. This implies the possibility of understanding concepts and ideas, visualized through conceptual models, without using linguistic or algebraic means. The proposed methodology is conducted in a metamodel-based tool environment whose aim is efficient application and ease of use.

Bioeconomic multistock reference points as a tool for overcoming the drawbacks of the landing obligation

Abstract: Dorleta Garcı́a1*, Raúl Prellezo1, Paz Sampedro2, José Marı́a Da-Rocha3,4, José Castro5, Santiago Cerviño5, Javier Garcı́a-Cutrı́n3, and Marı́a-José Gutiérrez6 Marine Research Division, Azti, Sukarrieta, Spain Instituto Español de Oceanografı́a, A Coruña, Spain University of Vigo, Vigo, Spain Instituto Tecnológico de México, ITAM, México Instituto Español de Oceanografı́a, Vigo, Spain University of the Basque Country (UPV/EHU), Bilbao, Spain

Envelope detection using generalized analytic signal in 2D QLCT domains

Abstract: The hypercomplex 2D analytic signal has been proposed by several authors with applications in color image processing. The analytic signal enables to extract local features from images. It has the fundamental property of splitting the identity, meaning that it separates qualitative and quantitative information of an image in form of the local phase and the local amplitude. The extension of analytic signal of linear canonical transform domain from 1D to 2D, covering also intrinsic 2D structures, has been proposed. We use this improved concept on envelope detector. The quaternion Fourier transform plays a vital role in the representation of multidimensional signals. The quaternion linear canonical transform (QLCT) is a well-known generalization of the quaternion Fourier transform. Some valuable properties of the two-sided QLCT are studied. Different approaches to the 2D quaternion Hilbert transforms are proposed that allow the calculation of the associated analytic signals, which can suppress the negative frequency components in the QLCT domains. As an application, examples of envelope detection demonstrate the effectiveness of our approach.

Atrial fibrillation episodes detection based on classification of heart rate derived features

Abstract: Atrial fibrillation (AF) is one of the most common cardiac arrhythmia and effects nearly 1–2 of every 100 persons of the population. This paper evaluates the effectiveness of Machine Learning (ML) approach to detect AF episodes. Features, determined exclusively on the basis of beat intervals, are classified with linear classifier. Performances of the proposed approach are evaluated by means of the MIT-BIH Atrial Fibrillation Database.

Introduction of accounting practices in small family businesses

Abstract: Purpose This research investigates the introduction of accounting practices into small family businesses, based on socioemotional wealth theory. Design/methodology/approach A multiple-case study was conducted gathering data through interviews and documents (proprietary and public). The sample included six businesses (five Mexican and one American) from different manufacturing and service industries. Findings It was found that, although owners control the implementation of accounting practices, others (including family employees, non-family employees and external experts) at times propose practices. The owner’s control can be relaxed, or even eliminated, as the result of proposals from some family employees. However, the degree of influence of family employees is not linked to the closeness of the family relationship, but rather to the owners’ perceived competence of the family employee, indicating an interaction between competence and experience on one side, and family ties on the other. Research limitations/implications First, the owners chose which documentary data to provide and who was accessible for interviews, potentially biasing findings. Second, the degree of influence family employees can exert might change over time. Third, the study included a limited number of interviews, which can increase the risk of bias. Finally, all firms studied were still managed by the founder. It is possible that small family businesses that have undergone a succession process might incorporate accounting practices differently. Practical implications Organizations promoting the implementation of managerial accounting practices should be aware that, in addition to the owner, some family employees and external experts could influence business practices. Accountants already providing accounting services to small family business are also a good source for proposing managerial accounting practices Originality/value This study contributes to theory in four ways. First, it expands socioemotional theory to include the perceived competence of the family employee as a potential moderator in the decision-making process. Second, it categorizes the actors who can influence managerial accounting practices in small family businesses. Third, it further refines the role of these actors, based on their degree of influence. Fourth, it proposes a model that describes the introduction of managerial accounting practices in small family business.

Can Outsourcing Improve Liberia's Schools? Preliminary Results from Year One of a Three-Year Randomized Evaluation of Partnership Schools for Liberia

Abstract: After one year, public schools managed by private contractors in Liberia raised student learning by 60 percent, compared to standard public schools. But costs were high, performance varied across contractors, and contracts authorized the largest contractor to push excess pupils and underperforming teachers onto other government schools.

Incentives for Replication in Economics

Abstract: Replication is a critical component of scientific credibility as it increases our confidence in the reliability of the knowledge generated by original research. Yet, replication is the exception rather than the rule in economics. In this paper, we examine why replication is so rare and propose changes to the incentives to replicate. Our study focuses on software code replication, which seeks to replicate the results in the original paper using the same data as the original study and verifying that the analysis code is correct. We analyse the effectiveness of the current model for code replication in the context of three desirable characteristics: unbiasedness, fairness and efficiency. We find substantial evidence of “overturn bias” that likely leads to many false positives in terms of “finding” or claiming mistakes in the original analysis. Overturn bias comes from the fact that replications that overturn original results are much easier to publish than those that confirm original results. In a survey of editors, almost all responded they would in principle publish a replication study that overturned the results of the original study, but only 29% responded that they would consider publishing a replication study that confirmed the original study results. We also find that most replication effort is devoted to so called important papers and that the cost of replication is high in that posited data and software are very hard to use. We outline a new model for the journals to take over replication post acceptance and prepublication that would solve the incentive problems raised in this paper.

Dialogue between theories interpreted as research praxeologies: the case of APOS and the ATD

Abstract: The notion of “praxeology” from the anthropological theory of the didactic (ATD) can be used as a framework to approach what has recently been called the networking of theories in mathematics education. Theories are interpreted as research praxeologies, and different modalities of “dialogues” between research praxeologies are proposed, based on alternatively considering the main features and proposals of one theory from the perspective of the other. To illustrate this networking methodology, we initiate a dialogue between APOS (action-process-object-schema) and the ATD itself. It starts from the theoretical component of both research praxeologies followed by the technological and technical ones. Both dialogue modalities and the resulting insights are illustrated, and the elements of APOS and the ATD that the dialogue can promote and develop are underlined. The results found indicate that a complete dialogue taking into account all components of research praxeologies appears as an unavoidable step in the networking of research praxeologies.

El efecto de los salarios mínimos en los ingresos laborales de México

Abstract: Este articulo analiza el efecto de los salarios minimos en los ingresos laborales en Mexico. Con paneles de datos de la Encuesta Nacional de Empleo Urbano (ENEU) y con los registros administrativos del Instituto Mexicano del Seguro Social (IMSS) se muestra que cambios en el salario minimo real tienen un efecto de signo positivo en el cambio de los ingresos laborales para todos los grupos salariales. El efecto es mas debil en los trabajadores que ganan varias veces el monto del salario minimo. Tambien se muestra que este efecto era mas grande en el periodo que abarca de 1985 a 1993 que entre 1994 y 2001, lo cual sugiere que este efecto esta perdiendo fuerza.