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.

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.

User Selection Algorithms for MU-MIMO Systems with Coordinated Beamforming

Fermín Marcelo Maciel-Barboza,Leonel Soriano-Equigua,Jaime Sánchez-García,Francisco Rubén Castillo-Soria,Victor Hugo Castillo Topete 한국전자통신연구원 2016 ETRI Journal Vol.38 No.1

In this paper, we propose two novel user selection algorithms for multiuser multiple-input and multiple-output downlink wireless systems, in which both a base station (BS) and mobile stations (MSs) are equipped with multiple antennas. Linear transmit beamforming at the BS and receive combining at the MSs are used to avoid interference between users and find a better sum-rate capacity performance. An optimal technique for selecting users would entail an exhaustive search, which in practice becomes computationally complex for a realistic number of users. Suboptimal algorithms with low complexity are proposed for a coordinated beamforming scheme. Simulation results show that the performance of the proposed algorithms is better than that provided by previous algorithms and is very close to an optimal approach with reduced complexity

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.

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.

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.

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.

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.

Changes in Heart Rate Variability in Patients with Spleen-Qi Deficiency Syndrome

Agnese Olivera-Toro,Rubén Fossion,Lei Li,Rosa E. López-Gómez,Emma López-Espinosa,Ismael Jiménez-Estrada,Salvador Quiroz-González 사단법인약침학회 2019 Journal of Acupuncture & Meridian Studies Vol.12 No.4

Many functional diseases are related to dysautonomia, and heart rate variability has been used to assess dysautonomia. However, heart rate variability has not been studied in Spleen-Qi deficiency syndrome (SQDS). Healthy volunteers (n Z 37) and patients with SQDS (n Z 67), recruited from the Clinic of the State University of Ecatepec Valley were included in the study. Outcome measures were average heart rate, standard deviation of the normal-to-normal heartbeat intervals, low frequency (LF), high frequency (HF) power, and the LF/HF ratio. Also, intestinal peristalsis, gastrointestinal symptoms (GSs), fatigue, and level of attention were measured. Standard deviation of the normal-to-normal heartbeat intervals (17 Æ 2.3%) and HF (14 Æ 3.1%) were lower in SQDS patients (17 Æ 1.3%) than in healthy volunteers. SQDS patients had higher heart rate, LF power, LF/HF ratio, and fatigue scores (9.6 Æ 1.12%, 16 Æ 2.1%, 22 Æ 3.8%, and 21 Æ 4.1%). The fatigue correlated positively with the LF/HF ratio and negatively with HF power. The SQDS group had lower concentration performance (16.2 Æ 1.9%) in the d2 test. The intestinal peristalsis showed a reduction (15 Æ 1.3%) as compared with control. GS score and peristalsis correlated negatively with HF. Our results suggest that the pathology of SDQS could be associated with a low vagal tone which causes a decrease in peristalsis, increased fatigue, reduced attention, and appearance of GSs.

PRPF8 increases the aggressiveness of hepatocellular carcinoma by regulating FAK/AKT pathway via fibronectin 1 splicing

López-Cánovas Juan L.,Hermán-Sánchez Natalia,del Rio-Moreno Mercedes,Fuentes-Fayos Antonio C.,Lara-López Araceli,Sánchez-Frias Marina E.,Amado Víctor,Ciria Rubén,Briceño Javier,de la Mata Manuel,Casta 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Hepatocellular carcinoma (HCC) pathogenesis is associated with alterations in splicing machinery components (spliceosome and splicing factors) and aberrant expression of oncogenic splice variants. We aimed to analyze the expression and potential role of the spliceosome component PRPF8 (pre-mRNA processing factor 8) in HCC. PRPF8 expression (mRNA/protein) was analyzed in a retrospective cohort of HCC patients (n = 172 HCC and nontumor tissues) and validated in two in silico cohorts (TCGA and CPTAC). PRPF8 expression was silenced in liver cancer cell lines and in xenograft tumors to understand the functional and mechanistic consequences. In silico RNAseq and CLIPseq data were also analyzed. Our results indicate that PRPF8 is overexpressed in HCC and associated with increased tumor aggressiveness (patient survival, etc.), expression of HCC-related splice variants, and modulation of critical genes implicated in cancer-related pathways. PRPF8 silencing ameliorated aggressiveness in vitro and decreased tumor growth in vivo. Analysis of in silico CLIPseq data in HepG2 cells demonstrated that PRPF8 binds preferentially to exons of protein-coding genes, and RNAseq analysis showed that PRPF8 silencing alters splicing events in multiple genes. Integrated and in vitro analyses revealed that PRPF8 silencing modulates fibronectin (FN1) splicing, promoting the exclusion of exon 40.2, which is paramount for binding to integrins. Consistent with this finding, PRPF8 silencing reduced FAK/AKT phosphorylation and blunted stress fiber formation. Indeed, HepG2 and Hep3B cells exhibited a lower invasive capacity in membranes treated with conditioned medium from PRPF8-silenced cells compared to medium from scramble-treated cells. This study demonstrates that PRPF8 is overexpressed and associated with aggressiveness in HCC and plays important roles in hepatocarcinogenesis by altering FN1 splicing, FAK/AKT activation and stress fiber formation.