Corporate Social Responsibility Impact on Business Performance through Green Supply Chain Management: Evidence from Guatemala

Rubén Avila García,박병주,장병윤 한국인터넷방송통신학회 2019 International Journal of Internet, Broadcasting an Vol.11 No.4

The purpose of this research is to examine the relationship between corporate social responsibility (CSR), green supply chain management (GSCM) practices, and business performances. After reviewing the extensive literature, we developed a research model including five constructs: CSR, GSCM practices, environmental, economic and operational performances. We conducted the statistical analyses based on the primary data collected from a survey questionnaire, responded by 93 different company managers in the Republic of Guatemala. Furthermore, we utilized structural equation modeling to analyze the data and to test the hypotheses. The results of the analyses showed that there is a significant influence of CSR on the adoption of GSCM practices. It was also found that GSCM practices have a significant influence on environmental, economic and operational performances. In addition, environmental performance has a significant impact on economic and operational performance. Finally, GSCM has a mediating role on the relationship between CSR and environmental and economic performance, but not with operational performance.

Stability Analysis of a Visual PID Controller Applied to a Planar Parallel Robot

Rubén Garrido,Miguel A. Trujano 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.6

This work analyses the stability of a standard PID controller fed by measurements provided by a vision system, and applied to a planar parallel redundant manipulator for constant set point tracking. The stability analysis considers uncertainty in the Jacobian matrix associated to the manipulator active joints, and constant disturbances perturbing these joints. The disturbances appear as time-varying at the visual level. Asymptotic stability of the closed loop system is proven using a Strict Lyapunov Function. The above allows directly applying the Lyapunov second method without resorting on the LaSalle-Krassovsky invariance theorem. The analysis also provides an upper bound on the allowable uncertainty in the Jacobian matrix. Experiments on a laboratory prototype permit evaluating the performance of a PID controller applied to a planar parallel robot.

Parental informal payments in Kyrgyzstani schools: Analyzing the strongest and the weakest link

Rubén Ruiz Ramas 한양대학교 아태지역연구센터 2016 Journal of Eurasian Studies Vol.7 No.2

This paper aims to explain why parental informal payments emerge and then spread in different manners in Kyrgyzstani schools and to examine their interaction as informal institutions with the school as a formal one. It is argued that the main reason behind informal payments is the survival of the schools; parents' acceptance of them was a result of necessity. In a small percentage of experiences where marketization of public schools was successful, there was a socioeconomic segregation of pupils, advancing toward a de facto privatization of public schools. Then, while the key logic behind informal payments was the upgrading or elitization of schools, the nature of the engagement of givers and receivers was by choice rather than by necessity. Finally, following Helmke and Levitsky (2004), I link the survival strategy to a substitutive relationship to formal public school outcomes, and to the elitization strategy, a competing nature with the formal logic of Kyrgyzstani basic education. Special attention is given to the social function approach toward informal economy practices, and to the significance of social stratification on how those informal practices work. The paper focuses on the comparison of informal payments in two schools representing the two strategies previously described: an elitnaya school from the center of Bishkek, the 13th Gymnasium School; and the conventional 21st Middle School in the novostroika (new settlement) of Enesay, the capital's periphery. The fieldwork of this research was developed in two stays during the months of July/August and October/November in 2011.

Parametric analysis based on energy and exergy balances of a condensing boiler

Rubén Arévalo-Ramírez,Javier Aros-Taglioni 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3

Condensing boilers are highly efficient equipment increasingly used to heat water for heating or industrial use, characterized by taking advantage of the residual heat of the combustion gases, including the condensation latent heat of water vapor. The present work analyzes important aspects to optimize the design and operation of this type of equipment from the energy and exergy point of view, specifically, the effect that changes in fuel, water inlet temperature (20-70 °C), excess air used in combustion (5-100 %) and relative humidity of the air (10-100 %), have on their energy and exergy efficiencies. For this purpose, the energy and exergy balance equations for the reactive and heat exchange processes that occur within it were implemented and solved using the computational program engineering equation solver (EES). The model was validated by comparing its results with the efficiency curve of a commercial condensing boiler model. The results show an important effect of the fuel type on the operating ranges in condensing and non-condensing modes and on the energy efficiency values, finding that the technology is widely justified when used with natural gas, and not so much with the other fuels analyzed. Likewise, a favorable effect of the reduction of excess air for combustion on energy efficiency can be seen, which is why it is advisable to operate this equipment with the least possible amount of air that guarantees good combustion. On the other hand, exergy efficiency has the highest values using natural gas, and benefits from a higher water return temperature and lower excess air. The greatest irreversibilities are found in the main coil and the combustion chamber.

Passivity‑based controller for a high‑energy‑quality active rectifier–DC motor system: an FPGA implementation

Rubén Heredia‑Barba,José Antonio Juárez‑Abad,Jesús Linares‑Flores,Marco Antonio Contreras‑Ordaz,Jorge Luis Barahona‑Ávalos 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.4

This study presents a passivity-based controller for a single-phase active rectifier–DC motor (SPAR-DCM) system. The mainobjective in the mechanical stage (DCM) is to regulate and maintain the desired angular speed of the motor under sudden load torque changes. Moreover, in the electric power stage, namely single-phase active rectifier (SPAR), the power factor (PF) should stay close to unity. We designed an Online Algebraic Estimator (OAE) to estimate the load torque parameter, adapted to the linear controller based on the exact static error dynamic passive output feedback (ESEDPOF) to minimize its effects. To synchronize the SPAR-DCM system with the grid, we used a second-order general integrator phase-locked loop to generate the necessary reference signals for the ESEDPOF controller. The arithmetic processing is programmed at mediumscale field-programmable gate array Spartan-6 XC6SLX16 through a detailed architecture design in 32 bits and in floating point, according to the standard IEEE-754. Experimental results verified the correctness and effectiveness of the proposed control algorithm. Furthermore, we demonstrated that the PF value is close to unity through power quality measurements.

The role of education in times of crisis: A critical analysis of the Europe 2020 Strategy

Rubén Arriazu,Mariana Solari 한국교육개발원 2015 KEDI Journal of Educational Policy Vol.12 No.2

The current economic crisis in Europe is accentuating social inequalities and promoting situations involving social injustice. The European Union has chosen to redefine its goals and realize growth, as outlined in the document known as Europe 2020 Strategy. This paper critically analyzes the economic and social values ​​underlying this document, with special attention to the role played by education in the current crisis. The results indicate that the educational objectives of Europe 2020 Strategy are grounded in neoliberal values and, consequently, increase social injustice. We advocate the importance of education as a means of transforming social and cultural reality.

Effectiveness of Resistance Exercise on Inflammatory Biomarkers in Patients with Type 2 Diabetes Mellitus: A Systematic Review with Meta-Analysis

Rubén Fernández-Rodríguez,Sonia Monedero-Carrasco,Bruno Bizzozero-Peroni,Miriam Garrido-Miguel,Arthur Eumann Mesas,Vicente Martínez-Vizcaíno 대한당뇨병학회 2023 Diabetes and Metabolism Journal Vol.47 No.1

Background: Type 2 diabetes mellitus (T2DM) is related to increased inflammatory processes. The effects of resistance exercise on inflammatory biomarkers in T2DM are controversial. Our purpose was to determine the effectiveness of resistance exercise on inflammatory biomarkers in patients diagnosed with T2DM.Methods: We searched four databases until September 2021. We included randomized clinical trials (RCTs) of the effects of resistance exercise on inflammatory biomarkers (C-reactive protein [CRP], tumor necrosis factor alpha, interleukin-6, and interleukin-10) in patients with T2DM. A random effects meta-analysis was conducted to determine the standardized mean difference (SMD) and the raw mean difference (MD) for CRP.Results: Thirteen RCTs were included in the review, and 11 in the meta-analysis for CRP. Lower CRP levels were observed when resistance exercise was compared with the control groups (SMD=–0.20; 95% confidence interval [CI], –0.37 to –0.02). When conducting the MD meta-analysis, resistance exercise showed a significant decrease in CRP of –0.59 mg/dL (95% CI, –0.88 to –0.30); otherwise, in the control groups, the CRP values increased 0.19 mg/dL (95% CI, 0.17 to 0.21).Conclusion: Evidence supports resistance exercise as an effective strategy to manage systemic inflammation by decreasing CRP levels in patients with T2DM. The evidence is still inconclusive for other inflammatory biomarkers.

Iron nanoparticles as food additives and food supplements, regulatory and legislative perspectives

Sara Madai Chavarría-Fernández,Rubén Jiménez-Alvarado,Eva María Santos-López,Aldahir Alberto Hernández-Hernandez,Raquel Cariño-Cortés 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.6

Recently, the use of nanotechnology in food has gained great interest. Iron nanoparticles with unique chemical, physical and structural properties allow their potential use mainly as iron fortifiers, colorants and antimicrobial agents. However, in the market we can find only supplements and food colorants based on iron nanoparticles. Their use in food fortification has so far been focused only on in vitro and in vivo experimental studies, since the toxicological evaluation of these studies has so far been the basis for the proposals of laws and regulations, which are still in an early stage of development. Therefore, the aim of this work was to summarize the use of the different forms of iron nanoparticles (oxides, oxyhydroxides, phosphates, pyrophosphates and sulfates) as food additives and supplements and to resume the perspectives of legislation regarding the use of these types of nanoparticles in the food industry.

A Delay-based Nonlinear Controller for Nanopositioning of Linear Ultrasonic Motors

Luis Luna,Kevin López,Rubén Garrido,Sabine Mondié,Luis Cantera 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.1

This work introduces a delay-based nonlinear controller aimed at position control of linear ultrasonic motors (LUMs), which is termed the cascade nonlinear proportional integral retarded (CNPIR) control law. This new controller incorporates a time delay in its structure, composed of two nested loops. The inner velocity loop is regulated through an integral retarded (IR) controller that contains a time delay in its structure. The outer position loop resorts to a nonlinear proportional (NP) controller endowed by a saturation function. A tuning procedure for the CNPIR controller is also proposed, and it is based on the placement of multiple dominant roots. The inner loop is tuned by assigning a dominant triple root, whereas a method based on solving a transcendental equation allows tuning the outer loop and assigns two dominant roots. Moreover, pole dominance is assessed through the argument principle. Experimental results on a linear ultrasonic motor allow assessing the real-time performance of the proposed controller to achieve high precision and fast response in spite of the effects of inner disturbances, hysteresis, and friction phenomena.

Host-ectoparasite associations; the role of host traits, season and habitat on parasitism interactions of the rodents of northeastern Iran

Hamidi Kordiyeh,Bueno-Marí Rubén 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Rodents play a significant role as reservoirs of zoonotic diseases. Nevertheless, in general their ectoparasite assemblage and host-ectoparasite associations are poorly known. This study intended to provide new insights into the relationships between ectoparasites and rodents in northeastern Iran. Rodents were captured using live traps during the years 2016–2020, and their ectoparasites were collected. Parasitological indices such as infestation rate, prevalence and mean intensity of infestation were analyzed. A total of 284 rodents, belonging to 17 species, were trapped and found to be infested by 178 ectoparasites from five orders Siphonaptera, Phthiraptera, Ixodida, Mesostigmata and Trombidiformes. The overall infestation rate was 50.3%. The flea Nosopsyllus fasciatus and the louse Polyplax asiatica dominated among all fleas and lice, respectively. Haemaphysalis punctata and Haemolaelaps sp. were recorded as the most abundant tick and mite, respectively. Nosopsyllus fasciatus exhibited low and Polyplax asiatica moderate host specificity. Approximately 64.2% of ectoparasites shared more than one host, and others were singletons. Seasonal fluctuations were found in the occurrence of ectoparasite; fleas and lice were more abundant in spring and winter, respectively. Ticks demonstrated high abundance in spring and summer and mites were more common in autumn. The overall prevalence of ectoparasite on male rodents was greater than that on females (56.4% vs. 44.4%), while similar mean intensities were detected for both sexes. This study extends the knowledge on the distribution, seasonality and host choice of four main groups of ectoparasites in association with rodents. Further studies are needed to provide deep insight into how relationships and interactions between ectoparasite and rodents are formed, and how they can be applied in epidemiology.