The impact of corporate governance and firm maturity on working capital management efficiency: Evidence from listed European firms

The importance of studying working capital management efficiency (WCME) springs from its effect on a firm’s profitability, value, and solvency. The board of directors together with the Chief Executive Officer formulate corporate policies including those concerning working capital levels, yet it is management’s role to continuously monitor the various working capital components to strike an optimal balance amongst them. Accordingly, this study analyses the effect of corporate governance in overseeing management handling working capital levels. In addition, this paper studies the role of firm maturity as a determinant factor of WCME. For this purpose, the paper at hand uses 583 listed European firms from 2002 till 2013. And, it employs cross section random effect panel regression models, where various working capital characteristics are used as dependent variables. And, along with the explanatory firm maturity proxy and the corporate governance variables, we control for the effect of country and multiple firm-specific characteristics. Finally, this study suggests that both corporate governance (except for ownership concentration proxy) and firm maturity are significant factors of WCME. Yet, for some of the proxies used, we did not reach conclusive results regarding the direction of impact on working capital investment

An Improved Method for the Processing of Signals Contaminated with Strong Common-Mode Periodic Noise in Correlation Velocity Measurement

Electrostatic sensors have been successfully used for the velocity measurement of pneumatically conveyed particles and the rotational speed measurement. However, the signal from an electrostatic sensor is usually vulnerable and susceptible to contamination in a hostile environment. The acquired original signal may be contaminated by different types of noise that can be within or outside the frequency range of the signal. This paper presents a novel correlation signal processing method to minimise the impact of noise in the signal through a de-noising process and hence improve the performance of correlation-based measurements in general. The method is applied to the rotational speed measurement based on electrostatic sensors in particular. The de-noising process is an essential task in digital signal processing to improve the signal-to-noise ratio before implementing the measurement algorithm. A hybrid de-noising method is proposed to combine a cut-off frequency method to remove the noise components outside the signal bandwidth and a median filter to smooth the signal. Subsequently, the signal is de-noised in the time domain by employing an advanced digital filtering method based on correlation techniques to suppress the noise frequency components mixed with the original signal. The rotational speed measurement system with the proposed technique has proven to be effective in de-noising signals that are buried in noise with which they are correlated. Moreover, the technique is capable of producing more accurate and repeatable measurements with a wider measurement range than the existing system. Experimental results suggest that the relative error of the improved system is mostly within ±0.1% over the speed range of 300 rpm - 3000 rpm and within ±0.2% over the speed range of 40-300 rpm

Vibration Measurement of an Unbalanced Metallic Shaft Using Electrostatic Sensors

Vibration measurement of a rotary shaft is essential for the diagnosis and prognosis of industrial rotating machinery. However, the imbalance of a shaft, as quantified through vibration displacement, is the most common cause of machine vibration. The objective of this study is to develop a novel technique through electrostatic sensing for the on-line, continuous and non-contact displacement measurement of a rotary shaft due to imbalance faults. A mathematical model is established to extract useful information about the shaft displacement vibration from the simulated signal in the frequency domain. Experimental tests were conducted on a purpose-built test rig to measure the displacement vibration of the shaft. An eccentric shaft was tested with the output signal from the electrostatic sensor analyzed. The effectiveness of the proposed method is verified through computer simulation and experimental tests. Results obtained indicate that the measurement system yields a relative error of within ±0.6% in the displacement measurement

Parallel Network Alert Management System For IDS False Positive Reduction

Every secure system has the possibility to fail. Therefore, extra effort should be taken to protect these systems. Intrusion detection systems (IDSs) had been proposed with the aim of providing extra protection to security systems. IDS is a powerful computer security system used to secure the computer environments. These systems trigger thousands of alerts per day, which prompt security analysts to verify each alert for relevance and severity based on an aggregation and correlation criterion. Several aggregation and correlation methods have been proposed to collect these alerts

Comparison of Single and Double Electrostatic Sensors for Rotational Speed Measurement

Accurate and reliable measurement of rotational speed is crucial in many industrial processes. Recent research provides an alternative approach to rotational speed measurement of dielectric rotors through electrostatic sensing and signal processing. This paper aims to explore the electrostatic phenomenon of rotational machineries, design considerations of the spacing between double electrostatic sensors and effect of dielectric rotors on the performance of the rotational speed measurement systems based on single and double electrostatic sensors. Through a series of experimental tests with rotors of different material types, including polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC) and Nylon, different surface roughness (Ra 3.2 and Ra 6.3) and difference diameters (60 mm and 120 mm), the accuracy and reliability of the two measurement systems are assessed and compared. Experimental results suggest that more electrostatic charge is generated on the PTFE rotors with a larger diameter and coarser surface and hence better performance of the measurement systems. The single-sensor system yields a relative error of within ±1% while the double-sensor system produces an error within ±1.5% over the speed range of 500 - 3000 rpm for all tested rotors. However, the single-sensor system outperforms the double-sensor system at high rotational speeds (>2000 rpm) with a relative error less than ±0.05%

Electrostatic Sensors – Their Principles and Applications

Over the past three decades electrostatic sensors have been proposed, developed and utilised for the continuous monitoring and measurement of a range of industrial processes, mechanical systems and clinical environments. Electrostatic sensors enjoy simplicity in structure, cost-effectiveness and suitability for a wide range of installation conditions. They either provide unique solutions to some measurement challenges or offer more cost-effective options to the more established sensors such as those based on acoustic, capacitive, optical and electromagnetic principles. The established or potential applications of electrostatic sensors appear wide ranging, but the underlining sensing principle and resultant system characteristics are very similar. This paper presents a comprehensive review of the electrostatic sensors and sensing systems that have been developed for the measurement and monitoring of a range of process variables and conditions. These include the flow measurement of pneumatically conveyed solids, measurement of particulate emissions, monitoring of fluidised beds, on-line particle sizing, burner flame monitoring, speed and radial vibration measurement of mechanical systems, and condition monitoring of power transmission belts, mechanical wear, and human activities. The fundamental sensing principles together with the advantages and limitations of electrostatic sensors for a given area of applications are also introduced. The technology readiness level for each area of applications is identified and commented. Trends and future development of electrostatic sensors, their signal conditioning electronics, signal processing methods as well as possible new applications are also discussed

Assessment of Cystatin C–Based GFR Estimating Equations as a Novel Reliable Biomarker for Renal Pathology Diagnosis in Patients with Mild to Severe Tubular Affection

Background and Objective: Creatinine, a commonly used biomarker in determining glomerular filtration rate (GFR) and chronic kidney disease (CKD) stage, is a highly variable biologically and does not rise until > 50% of renal function (RF) impairment, resulting in erroneous CKD grading. Applying a simple and reliable GFR estimate approach aimed at a minute evaluation of RF might be of tremendous therapeutic value. So, our investigation was aimed to assess Cystatin (Cys) -C-based eGFR equations, a novel, more sensitive biomarker in kidney pathology, and less susceptible to biological interference. Methods: This cross-sectional study was performed on 20 CKD cases who attended the Nephrology Department at Ain Shams University, where a renal biopsy was obtained, and individuals were allocated into two categories: cases with mild tubular affection (TA) [category A] and with moderate to severe TA [category B]. All participants were referred for measurement of Cys-C Level using different GFR-estimating equations, which further compared using Multivariate Linear Regression and Bland-Altman analyses. Results: Our results revealed a substantial statistical difference among the two studied categories regarding Hb, kidney function tests. A significant correlation between CKD-EPI CYST and mGFR was measured by Iohexol (Ioh) for category A (R=0.601, P=0.030), where there was a non-substantial relation between any of the used equations and mGFR in category B (p > 0.05). There was no independent association between the eGFR results and Iohexol clearance. Stevens eGFR had the highest-level bias 33.9 compared with CKD_EPI_CYST (28) and Grubb eGFR (22.85), Conclusion: Although cystatin-based equations have demonstrated a high level of correlation with measured Iohexol GFR, they are still deemed imprecise and cannot be established as equal to assessed GFR or as a gold standard for GFR estimate

Effect of hemodiafiltration on sclerostin level and bone specific alkaline phosphatase in comparison with high flux dialysis

 Background: Sclerostin (sScl), an osteocyte-derived glycoprotein acts as a soluble inhibitor of the Wnt signaling pathway and bone formation. Its serum levels increase with the progression of CKD. The present study investigated the effect of hemodiafiltration (HDF) on sScl and bone specific alkaline phosphatase (BS-AP) in comparison with high flux hemodialysis (HF-HD). Methods: a prospective study was conducted upon 32 ESRD patients; 16 on regular HF-HD and 16 shifted to 3 months of HDF. Results: There was a significant reduction of predialysis sScl and BS-AP with a significant increase in sScl reduction ratio in the HDF group after 3months. SScl had a significant positive correlation with total but not BS-AP. Conclusion: sScl and BS-AP significantly decrease but are poorly correlated with each other in HDF. So either sScl reduction does not translate into better bone turnover or the BS-AP is not a suitable biomarker to assess bone turnover in HDF.

Desarrollo de un componente Web parametrizable para la visualización de datos científicos

Auxiliar de InvestigaciónEste proyecto se fundamentó en el desarrollo de un componente Web parametrizable para la visualización de datos científicos, el cual permitirá a futuro, con integración de otros componentes, establecer un análisis visual de los datos extraídos, enfocado en la necesidad del usuario.1. GENERALIDADES 2. OBJETIVOS DEL PROYECTO 3. MARCO DE REFERENCIA 4. MARCO CONCEPTUAL 5. METODOLOGÍA 6. DESARROLLO DEL PROYECTO 7. RESULTADOS 8. CONCLUSIONES 9. TRABAJOS FUTUROS 10. BIBLIOGRAFÍA 11. GLOSARIO 12. ANEXOSPregradoIngeniero de Sistema

Development of an International Odor Identification Test for Children: The Universal Sniff Test

Objective: To assess olfactory function in children and to create and validate an odor identification test to diagnose olfactory dysfunction in children, which we called the Universal Sniff (U-Sniff) test.  Study design: This is a multicenter study involving 19 countries. The U-Sniff test was developed in 3 phases including 1760 children age 5-7 years. Phase 1: identification of potentially recognizable odors; phase 2: selection of odorants for the odor identification test; and phase 3: evaluation of the test and acquisition of normative data. Test—retest reliability was evaluated in a subgroup of children (n = 27), and the test was validated using children with congenital anosmia (n = 14).  Results: Twelve odors were familiar to children and, therefore, included in the U-Sniff test. Children scored a mean ± SD of 9.88 ± 1.80 points out of 12. Normative data was obtained and reported for each country. The U-Sniff test demonstrated a high test—retest reliability (r27 = 0.83, P < .001) and enabled discrimination between normosmia and children with congenital anosmia with a sensitivity of 100% and specificity of 86%.  Conclusions: The U-Sniff is a valid and reliable method of testing olfaction in children and can be used internationally