Controlling Variables Research Articles

Diagnosis of environmental controls on daily actual evapotranspiration across a global flux tower network: the roles of water and energy

Relative contributions from environmental factors to daily actual evapotranspiration (ETa) across a variety of climate zones is a widely open research question, especially regarding the roles played by soil water content ((SWC); water supply) and net radiation ((Rn); energy supply) in controlling ETa. Here, the boosted regression tree method scheme was employed to quantify environmental controls on daily ETa using the global FLUXNET dataset. Similar to the general trend suggested by the Budyko theory at annual scales, the results showed that the relative control of SWC on daily ETa increased with increasing aridity index (Φ); however, Rn played a major role at most FLUXNET sites (roughly Φ < 4), indicating that Rn could be a leading control on daily ETa even at water-limited sites. The variability in the relative controls of SWC and Rn also partly depended on factors affecting water availability for daily ETa (e.g. vegetation characteristics and groundwater depth). Our study showed that other than SWC and Rn, the net effect of environmental controls (particularly leaf area index) on daily ETa was more important at drier sites than at relatively humid sites. This suggests that near-surface hydrological processes are more sensitive to vegetation variations due to their ability to extract deep soil water and enhance ETa, especially under arid and semi-arid climatic conditions. Our findings illustrate how environmental controls on daily ETa change as the climate dries, which has important implications for many scientific disciplines including hydrological, climatic, and agricultural studies.

Adjustment of Multiple Variables for Optimal Control of Building Energy Performance via a Genetic Algorithm

Optimizing the operating conditions and control set points of the heating, ventilation, and air-conditioning (HVAC) system in a building is one of the most effective ways to save energy and improve the building’s energy performance. Here, we optimized different control variables using a genetic algorithm. We constructed and evaluated three optimal control scenarios (cases) to compare the energy savings of each by varying the setting and number and type of the optimized control variables. Case 1 used only air-side control variables and achieved an energy savings rate of about 5.72%; case 2 used only water-side control variables and achieved an energy savings rate of 16.98%; and case 3, which combined all the control variables, achieved 25.14% energy savings. The energy savings percentages differed depending on the setting and type of the control variables. The results show that, when multiple control set points are optimized simultaneously in an HVAC system, the energy savings efficiency becomes more effective. It was also confirmed that the control characteristics and energy saving rate change depending on the location and number of control variables when optimizing using the same algorithm.

The Effect of Internal Control, Information Technology and Audit on Good Amil Governance Practices

This research aimed to find out how strong the effect of the implementation of internal control, information technology and audit on Good Amil Governance. In this research, the respondents were the chief and amil at BAZNAS in South Kalimantan. The type of this research was exploratory with data collection technique using questionnaire. Data analysis method that was used in this research was descriptive analysis method, Structural Equation Modeling (SEM) with software of SmartPLS 3.0. The research result showed that the variables of internal control, information technology, and audit had significant and positive effect on good amil governance.

Smart Box Development for Food Storage with PCI-Based Temperature PID Control

Temperature measurement with a control system aims to improve the quality of automation processes in the field of instrumentation, automatic systems and especially food production. The primary function of the control system is to maintain predetermined or changeable variables under specified conditions. The control system is determined by three factors, namely, process variables, controller variables and manipulated variables. In this study, the temperature response was measured in an acrylic box with a size of 30×30×20 cm3 using a PT100 sensor. The temperature response was verified with a PID control system integrated with LabVIEW software and acquired by a PCI 6221 card. The PT100 sensor calibration with the Voltcraft digital temperature shown a linear relationship. The results of the temperature response test with the PI system produced P and I parameters of 9.03 and 2.7 min, respectively, while in the PID system the P, I and D parameters were 13.2, 6.2 min and 0.2 min, respectively. The response of the control system with the PI type is more stable and consistent than the PID type. Based on the results obtained, the temperature control process using a PI or PID control system with a TD value of 0 is more recommended.

Permanent postoperative hypoparathyroidism: an analysis of prevalence and predictive factors for adequacy of control in a cohort of 260 patients.

Recent guidelines for the treatment of hypoparathyroidism emphasize the need for long-term disease control, avoiding symptoms and hypocalcaemia. Our aim has been to analyze the prevalence of poor disease control in a national cohort of patients with hypoparathyroidism, as well as to evaluate predictive variables of inadequate disease control. From a nation-wide observational study including a cohort of 1792 patients undergoing total thyroidectomy, we selected 260 subjects [207 women and 53 men, aged (mean ± SD) 47.2±14.8 years] diagnosed with permanent hypoparathyroidism. In every patient demographic data and details on surgical procedure, histopathology, calcium (Ca) metabolism, and therapy with Ca and calcitriol were retrospectively collected. A patient was considered not adequately controlled (NAC) if presented symptoms of hypocalcemia or biochemical data showing low serum Ca levels or high urinary Ca excretion. Two hundred and twenty-one (85.0%) patients were adequately controlled (AC) and 39 (15.0%) were NAC. Comparison between AC and NAC patients did not show any significant difference in demographic, surgical, and pathological features. Rate of hospitalization during follow-up was significantly higher among NAC patients in comparison with AC patients (35.9% vs. 10.9%, P<0.001). Dose of oral Ca and calcitriol were also significantly higher in NAC subjects. In a subgroup of 129 patients with serum parathyroid hormone (PTH) levels available, we found that NAC patients exhibited significantly lower postoperative PTH concentrations than AC patients [median (interquartile range) 3 (1.9-7.8) vs. 6.9 (3.0-11) pg/mL; P=0.009]. In a nation-wide cohort of 260 subjects with definitive hypoparathyroidism, 15% of them had poor disease control. These patients required higher doses of oral Ca and calcitriol, had higher rate of hospitalization during follow-up and showed lower PTH concentrations in the postoperative period.

Study of Women's Social Security and Social Factors Affecting it (Case Study of Young Women Aged 15-64 in Babol)

The Social security of any society is one of the basic needs. Security in its objective sense is the measure of the absence of a threat to values; The purpose of this study is to investigate social security and social factors affecting it among women in Babol and its application.The present study is based on a survey method that the statistical population of young women aged 15-39 years in two urban areas of Babol and using the Cochran's formula, the sample size of a sample of 400 people was selected from the sample method. The questionnaire was used for data collection and the validity of the data was formal validity and its reliability was measured by Cronbach's. Analysis of variance, Pearson correlation, multivariate regression and factor analysis were used for the relationship between independent and dependent variables. The results show that there is a significant and direct relationship between the independent variables of social control, social support, social trust and the dependent variable of social security. Multivariate regression analysis shows that independent variables (0.22) explain the percentage of changes in social security.

Gain-scheduled control for morphing aircraft via switching polytopic linear parameter-varying systems

This paper addresses the gain-scheduled output feedback control for morphing aircraft (MA) in full envelope using switching polytopic linear parameter-varying (SPLPV) theory. The SPLPV model of MA is derived by scheduled parameter interval division and convex decomposition. Considering average dwell time (ADT) and mode-dependent average dwell time (MDADT) switching logics, sufficient conditions to ensure that the SPLPV systems are exponential stable with weighted disturbance attenuation indexes are presented based on the multiple parameter-dependent Lyapunov functions (MPDLFs) technique, and the comprehensive algorithm for the controller solution is obtained. To reduce the computational burden and ease controller implementation, a finite number of linear matrix inequalities (LMIs) are developed for solving controller by proposing the intermediate controller variables are depend affinely on the scheduled parameter. In addition, the control matrix of linear parameter-varying (LPV) system is not limited to be constant, which greatly expands the application scope of the proposed method. The simulation validation is carried out on the SPLPV control for MA.

Reliability of postural control during double-leg standing in subjects with nonspecific chronic low back pain: Dual-task paradigm and manipulated visual and somatosensory inputs

BackgroundThe aim of this study is to evaluate the test-retest reliability of the Center of Pressure (COP) parameters in quiet double-leg standing in subjects with Non-Specific Chronic Low Back Pain (NSCLBP) during dual taking associated with manipulated visual and somatosensory inputs. Materials and methodsIn this observational cross-sectional study, the static balance of thirty NSCLBP patients were assessed during a double-leg stance by using the force platform. Subjects were accosted by manipulated somatosensory and visual inputs during dual taking in eight different conditions (with and without vibration, eyes-open and eyes-closed, and with and without auditory Stroop test). The COP parameters were recorded as follows: range sideways and range fore-aft as well as mean velocity and area variables. The cognitive task parameters included the reaction time and error ratio. The intra-class correlation coefficient (ICC) was computed to assess the intersession reliability of COP parameters. Resultsin intersession, range sideways, range fore-aft, and mean velocity measures possessed moderate to high ICC, but area owned high ICC only in one condition (double-leg stance, eyes-close, with vibration, and with auditory Stroop test). Notably, other conditions had low ICC, and moderate to high and low to very high ICC were reported for reaction time and error ratio. ConclusionAmong the parameters studied in the present study, the mean velocity measure seems to be the most reliable variable of postural control in the subjects with NSLBP especially in more challenging conditions, i.e., quiet double-leg standing with eyes closed and adding vibratory inputs during dual-tasking.

Application of Multi-Attribute Decision Making Method Based on Normal Random Variables in Risk Control of Economic Management

Application of Multi-Attribute Decision Making Method Based on Normal Random Variables in Risk Control of Economic Management

Effect of Trimming Process Parameters on Sheared Edge Geometry and Stretch Limit: An Experimental Investigation

The stretchability and flangeability of sheared sheet metal in stamping are directly influenced by the trimmed edge quality. In this work, the effect of the trimming parameters on the edge quality was investigated using experimental and statistical approaches. The material of study was a 6xxx-series aluminum sheet. A digital 3D optical microscope was used to assess the quality of the sheared edge geometry by measuring several distinct trimmed edge geometrical features, namely rollover, burnish, fracture, and burr. The evolution of the sheared edge geometry was studied by changing four trimming parameters, namely clearance, offal support, lower tool sharpness, and upper tool sharpness. The sheared edge’s ability to stretch was assessed by measuring both the total elongation and the local strain of trimmed half dog-bone specimens tested under uniaxial tensile loading conditions. A generalized linear model regression was used to investigate the relationship between the edge stretch, edge geometry, and trimming process parameters. The burr size was found to be the most significant factor for predicting elongation, while clearance between the upper tool and the lower tool was found to be the most significant controllable regression variable. Furthermore, the use of high support was reported to decrease the sensitivity of the trimmed edge quality to the upper and lower tool sharpness.

Brain-derived neurotrophic factor (BDNF) levels in first-episode schizophrenia and healthy controls: A comparative study.

Abnormalities in brain development and plasticity have been associated with the pathophysiology of schizophrenia. The role of brain-derived neurotrophic factor (BDNF) in schizophrenia is the recent area of interest because it regulates neurogenesis. The current study aimed to assess and compare serum BDNF levels between first-episode schizophrenia patients and healthy controls, and evaluate its correlation with the socio-demographic and clinical variables. It was a cross-sectional comparative study for the assessment of serum BDNF levels between patients with first-episode schizophrenia (N=50) and healthy controls (N-50) conducted in the Department of Psychiatry at a tertiary care public hospital attached to a medical school in North India. Participants were assessed for the socio-demographic parameters, nicotine dependence, and clinical details using structured scales. Serum BDNF level estimated using the sandwich ELISA technique. The comparison between the groups was done by using a Student t-test or chi-square test. Spearman correlation was performed between mean BDNF scores and demographic or illness variables in both first-episode schizophrenia and healthy control groups. There was a significantly lower mean score of total serum BDNF levels in first-episode schizophrenia patients as compared to controls (8.44 ± 1.54 vs 10.44 ± 2.04; t = 5.52, p < 0.001; 95% CI = 1.28-2.71). The total FTND scores for smokeless tobacco use were negatively correlated to BDNF levels among healthy controls (r=-0.30, p=0.03) as well as in the first-episode schizophrenia group (r=-0.32, p= 0.04). None of the other illness-related variables were correlated to serum BDNF values in the first episode schizophrenia group. Individuals with first-episode schizophrenia have lower serum BDNF levels than healthy controls. The illness-related factors such as duration of untreated psychosis or psychopathology were not correlated with BDNF levels. Thus abnormal signaling of BDNF can lead to abnormal brain functioning which can make an individual more susceptible to schizophrenia.

Numerical simulation of the influence of external urban environmental conditions in the building windows performance

This paper presents a numerical study of the influence of external urban environmental conditions, namely, the solar radiation, in the building windows performance. A software that simulates the building thermal behaviour with complex topology, in transient conditions, is developed and used in the study of indoor air quality and indoor thermal comfort of the occupants of a building, under typical summer conditions. As management strategy was implemented a control system to the Heating, Ventilation and Air Conditioning (HVAC) using the PMV (Predicted Mean Vote) index as controllable variable. The studied university building is located in a Mediterranean-type climate in the south of Portugal. The indoor thermal comfort, evaluated by the PMV index, and the indoor air quality, evaluated by the carbon dioxide concentration, were obtained for all occupied spaces. In order to evaluate the implemented control strategy a set of results was obtained for the situations with and without HVAC system control. To exemplify the results obtained, two large compartments were chosen, one with windows facing South and the other without windows. As main conclusion, it can be stated that the use of the HVAC system controllable by the PMV index allows acceptable levels of thermal comfort within the category C of the ISO 7730 standard, and acceptable levels of indoor air quality within the limit proposed by the ASHRAE 62.1 standard.

Antecedents and effects of boredom among university students: an integrated conditional process model

Boredom coping strategies were incorporated with control-value theory variables of control, value, boredom and academic performance to test an integrated model of the antecedents and effects of boredom experienced while studying among university students. A diverse sample of 177 Australian university students with a mean age of 29.64 years (SD = 10.03 years) completed an online survey for the study. Independently, students’ lower appraisals of value and control for their course of study were associated with higher experiences of boredom. Additionally, a conditional process analysis revealed dually moderated mediation where the interaction of control and value appraisals negatively predicted experience of boredom while studying, and the combination of higher boredom and a high tendency for behavioural avoidance coping was subsequently linked to lower academic performance. Practical implications for students and universities are discussed, as well as suggestions about future research to further extend our understanding in these important areas of research.

Analisis intensi dosen dalam implementasi Kurikulum berbasis kkni di iain kediri

The origin of Presidential Regulation No. 08/2012 concerning the Indonesian National Qualification Framework (KKNI) is oriented as a framework for qualifying the competency level of graduates who can juxtapose, equalize, and integrate education, training fields and work experiences. Each educational institution attempts to establish higher education that is able to produce graduates who have attitudes, knowledge, and skills that meet the expectations of the society and the stakeholders by implementing the KKNI-based curriculum. The teachers who become the primary sample in this study are the spearhead of the implementers in the process of implementing the curriculum in higher education. This research employs a quantitative approach with correlational design. Data collection was carried out through a questionnaire distributed to 109 IAIN Kediri teachers spread across all departments. Furthermore, the data were analyzed by using descriptive statistics, Pearson product-moment correlation, ANOVA, and multiple regression. Based on the analysis tool, it is known that the variables of attitude, subjective norms, and behavioral control simultaneously influence teachers 'intentions in the implementation of the IQF-based curriculum. However, it is found that only partially subjective norms and behavioral control variables bring a significant effect on teachers' intentions in implementing the KKNI-based curriculum at IAIN Kediri

Developing an Eco-Friendly Indigo Dyeing System by Using Baker’s Yeast (Saccharomyces Cerevisiae): Some Variables Related to pH Control and Scale-Up

The aim of this study was to elucidate some fundamental variables for applying baker’s yeast (Saccharomyces cerevisiae) to natural indigo (Indigofera tinctoria) dyeing. The variables of pH control, bath reuse, scale-up of reduction bath, and repeat dyeing were chosen for this study. The reducing power was evaluated based on the oxidation-reduction potential (ORP), and the color yield (K/S value) of ramie fabric dyed. When the pH was not controlled, K/S higher than 12 lasted for only 3 days. With pH control, the duration was extended to 29–36 days. By supplementing yeast at the end of reduction, the reducing power was revived for approximately 30 days. A deeper and darker blue color was obtained for all fabrics, including cotton, ramie, wool, and nylon 6, by repeat dyeing than by one-time dyeing. Additionally, wool and nylon 6 showed broader blue color spectra than cotton and ramie. With pH control and repeated dyeing in the scale-up bath, yeast reduction could be developed into a microbial indigo dyeing process as an alternative to conventional chemical reduction.

ACE2 gene variants may underlie interindividual variability and susceptibility to COVID-19 in the Italian population

In December 2019, an initial cluster of interstitial bilateral pneumonia emerged in Wuhan, China. A human-to-human transmission was assumed and a previously unrecognized entity, termed coronavirus disease-19 (COVID-19) due to a novel coronavirus (SARS-CoV-2) was described. The infection has rapidly spread out all over the world and Italy has been the first European country experiencing the endemic wave with unexpected clinical severity in comparison with Asian countries. It has been shown that SARS-CoV-2 utilizes angiotensin converting enzyme 2 (ACE2) as host receptor and host proteases for cell surface binding and internalization. Thus, a predisposing genetic background can give reason for interindividual disease susceptibility and/or severity. Taking advantage of the Network of Italian Genomes (NIG), here we mined whole-exome sequencing data of 6930 Italian control individuals from five different centers looking for ACE2 variants. A number of variants with a potential impact on protein stability were identified. Among these, three more common missense changes, p.(Asn720Asp), p.(Lys26Arg), and p.(Gly211Arg) were predicted to interfere with protein structure and stabilization. Rare variants likely interfering with the internalization process, namely p.(Leu351Val) and p.(Pro389His), predicted to interfere with SARS-CoV-2 spike protein binding, were also observed. Comparison of ACE2 WES data between a cohort of 131 patients and 258 controls allowed identifying a statistically significant (P value < 0.029) higher allelic variability in controls compared with patients. These findings suggest that a predisposing genetic background may contribute to the observed interindividual clinical variability associated with COVID-19, allowing an evidence-based risk assessment leading to personalized preventive measures and therapeutic options.

Characterization of Predictive Control Based on Model (MPC) in Multivariable Process of Milling in a Mineral Concentrator Plant

In this article, the simulation level characterization of the predictive control system -based in multivariable model (MPC) is developed, without restrictions in a milling process of a mineral concentrator plant. The multivariability of the process is considered and is evaluated the interaction between the variables. The control strategy that integrates all the control actions is developed, assessing the robustness in the application against disturbances. Generalized predictive control (GPC) is used, presenting the methodology in accordance with the philosophy of predictive control MPC, based on an initial modeling of the process, developed in reference [1]. The case study includes the use of a ball mill in a process of 4 input variables by 4 output (MIMO 4x4), where one of the output variables of greater control is the size of the mineral particles in an iron mine. The results of the control are evaluated observing and discussing the temporal responses in all the variables, the robustness of the control system is evaluated considering the response of the system before the application of multiple disturbances. Results are presented in various simulation scenarios using MATLAB.

Partial nitritation with aerobic duration control of carbon-captured blackwater: Process operation and model-based evaluation

Partial nitritation and anammox (PN/Anammox) is the most appropriate process for nitrogen removal from blackwater. However, information on control strategies of PN of blackwater is scarce. In this study we selected aerobic duration control, with pH and dpH/dt as control variables, as our PN strategy. To demonstrate PN with aerobic duration control, investigate impact factors, and optimize start-up and the operation process, a laboratory-scale PN-SBR (sequencing batch reactor), fed on real carbon-captured blackwater (321 mg COD/L, 219 mg N/L, pH 8.18, and alkalinity 804 mg CaCO3/L) was set up. A model-based evaluation was implemented. With aerobic duration control, the PN-SBR was successfully started in ∼2 weeks, reaching an average nitrite accumulation ratio (NAR) of 93.8% at 30 °C with a sludge retention time of 8.1 days. Low dissolved oxygen (0.30 mg/L) had minimal effect on the NAR, but significantly prolonged the reaction period. One week, on-site free nitrous acid and free ammonia sludge shock treatments had limited effect on the PN process, and could not prevent lasting washout of the nitrite-oxidizing organisms. When the temperature was decreased from 20 °C to 15 °C, the NAR decreased from 95.6% to 88.6%, due to the nitrite-oxidizing organisms in the influent, as indicated by our modeling results. We found pH to be a better controlling variable than dpH/dt as it not only shortened the reaction period, but also resulted in good PN performance. Fixed pH is also an appropriate control variable for the fluctuating alkalinity-to-ammonium ratio. In conclusion, aerobic duration control is an appropriate strategy to achieve PN of carbon-captured blackwater.

Investigating the Relationship between Job Compatibility and Controlling Job Stress with Nurses' Performance: A Case Study on Shiraz State Hospitals

Introduction: Performance is considered as the predicted criterion in the framework offered in this study. This framework serves as a tool for judging the effectiveness of individuals, groups, and organizations. This study aimed to investigate the relationship between job compatibility and controlling job stress with nurses' performance in 2020. Methods: The present study was performed by a descriptive-correlation method with applied nature in 2020. The statistical population includes nurses working in Shiraz state hospitals (Namazi, Shahid Faghihi, and Hafez). The sample size was calculated according to Cochran's formula of 196 nurses and the sampling method was performed in Stratified Sampling. In this study, researchers’ self-made questionnaire with three main sections, 13 questions, and a five-option Likert scale was used, from completely agree to disagree. Cronbach's alphas reliability was calculated to be 77.4 in the questionnaire and its validity was obtained using the opinion of experts. Statistical analysis was performed using SPSS ver. 22 software and to examine the normality of the data, the Kolmogorov-Smirnov test was used. Due to the non-normality of the data, Spearman test, Durbin-Watson statistics, statistics F and statistics T and regression model have been used at a confidence level of %95. Results: According to statistical analysis, the mean and standard deviation of the variable of job compatibility were 3.368 and 1.15, the variable of job stress control were 3.084, 1.17, and the variable of the performance of nurses were 3.408 and 1.02. Also, the Coefficient of determination is 0.887, and Spearman's correlation at a significance level of 0.001 between job compatibility with a performance of 0.731 and stress control with performance is calculated as 0.651. Conclusion: Job compatibility leads to people’s effective performance and a positive attitude towards the new job role, and also reduces the high level of stress. Furthermore, work stress causes physical and psychological damage, so personal and organizational performance will be improved by controlling it.

Smart machining: Monitoring of CFRP milling using AE and IR

In aerospace industry, polymers reinforced with carbon fibre offer several advantages, such as weight/strength ratio and corrosion resistance. However, the manufacturing process is complex, especially the machining of composite materials, due to their specific properties and characteristics. The detection and prediction of surface finishing and occurrence of defects during manufacturing using non-destructive techniques is industrially useful, in terms of fomenting automated manufacturing systems to increase productivity and quality control. Acoustic emission signal processing is being successful in mechanical tests for determining material defects, more recently used as a method for manufacturing evaluation of machined parts. This paper focused in the machining process of CFRP plate, in terms of surface finishing evaluation with comprehension of process phenomenology using analyses of temperature and acoustic emission signal features. The aim of this paper is to show the possibility of online monitoring of the cutting process and to understand mechanism behind variables of control, with comparisons of different milling parameters and focusing in their impacts in acoustic emission signals and surface finishing, with suggestions of evaluation and prediction methods of machined surface quality using mainly acoustic emission signals.