Index Variables Research Articles

GARCH-type forecasting models for volatility of stock market and MCS test

ABSTRACTThe prediction of time-changing volatility is an important task in the modeling of financial data. In the paper, a comprehensive analysis of the mean return and conditional variance of SSE380 index is performed to use GARCH, EGARCH and TGARCH models with Normal innovation and Student's t innovation. Conducting a bootstrap simulation study which shows the Model Confidence Set (MCS) captures the superior models across a range of significance levels. The experimental results show that, under various loss functions, the GARCH using Student's t innovation model is the best model for volatility predictions of SSE380 among the six models.

To be committed or not: examining effects of personal and workplace variables on the organizational commitment of Southern prison staff

This study examined how personal and workplace variables were related to organizational commitment among staff working at a large Southern prison. The personal variables were gender, age, position, tenure, educational level, and supervisory status. The workplace variables were assessment of training, job variety, role clarity, input into decision-making, and instrumental communication. The results indicate workplace variables play a greater role in shaping affective commitment of surveyed Southern prison staff than do personal variables. The personal variables explained only 10% of the variance in the commitment index, while workplace factors accounted for approximately 59% of the variance and were significant determinants of organizational commitment among the respondents. In the multivariate regression analysis, age, assessment of training, job variety, role clarity, input into decision-making, and instrumental communication all had positive associations with commitment. Educational level had a negative relationship with commitment. Implications of these findings for policy and future research are also discussed.

Optical Phase Measurements of Disorder Strength Link Microstructure to Cell Stiffness

There have been sustained efforts on the part of cell biologists to understand the mechanisms by which cells respond to mechanical stimuli. To this end, many rheological tools have been developed to characterize cellular stiffness. However, measurement of cellular viscoelastic properties has been limited in scope by the nature of most microrheological methods, which require direct mechanical contact, applied at the single-cell level. In this article, we describe, to our knowledge, a new analysis approach for quantitative phase imaging that relates refractive index variance to disorder strength, a parameter that is linked to cell stiffness. Significantly, both disorder strength and cell stiffness are measured with the same phase imaging system, presenting a unique alternative for label-free, noncontact, single-shot imaging of cellular rheologic properties. To demonstrate the potential applicability of the technique, we measure phase disorder strength and shear stiffness across five cellular populations with varying mechanical properties and demonstrate an inverse relationship between these two parameters. The existence of this relationship suggests that predictions of cell mechanical properties can be obtained from examining the disorder strength of cell structure using this, to our knowledge, novel, noncontact technique.

Variação sanguínea nas artroplastias de joelho com e sem o uso de garrote

ObjectiveTo evaluate the difference between the total blood loss in patients undergoing primary total knee arthroplasty with and without the use of tourniquet. MethodsA retrospective cohort study, with analysis of medical records of patients undergoing primary total knee arthroplasty in 2015, with and without the use of a tourniquet. Comparison was performed of hemoglobin (HB) and hematocrit (HT) variation in the complete blood count (CBC) during the pre‐ and post‐operative period between the two groups. ResultsThere were 117 patients undergoing primary total knee arthroplasty included, minimum age of 33 and maximum of 86 years, with a mean of 67 years. 64.1% of the surgeries used a tourniquet and 35.9% did not. The mean preoperative HB in Group 1 was 13.08 and 12.97 in Group 2 (p=0.435). The mean postoperative HB in Group 1 was 11.64 and 10.93 in Group 2 (p=0.016). The variation of HB in Group 1 was 1.44 and 2.04 in Group 2 (p=0.025). The mean preoperative HT in Group 1 was 38.96 and 39.01 in Group 2 (p=0.898). The mean postoperative HT in Group 1 was 34.47 and 32.19 in Group 2 (p=0.005). The variation of HT in Group 1 was 4.49 and 6.82 in Group 2 (p=0.001). A total of 21 patients received transfusions RCC (red cell concentrates), as a result of HB below 8g/dL or clinical symptoms, respectively, representing seven of Group 1 (9.3% of total intra‐group) and 14 of Group 2 (33.3% of total intra‐group), with p=0.001. ConclusionIn patients undergoing primary total knee arthroplasty using a tourniquet, a lower variance in the hematimetric indices was observed and fewer blood transfusions were necessary.

Refractive index variance of cells and tissues measured by quantitative phase imaging.

The refractive index distribution of cells and tissues governs their interaction with light and can report on morphological modifications associated with disease. Through intensity-based measurements, refractive index information can be extracted only via scattering models that approximate light propagation. As a result, current knowledge of refractive index distributions across various tissues and cell types remains limited. Here we use quantitative phase imaging and the statistical dispersion relation (SDR) to extract information about the refractive index variance in a variety of specimens. Due to the phase-resolved measurement in three-dimensions, our approach yields refractive index results without prior knowledge about the tissue thickness. With the recent progress in quantitative phase imaging systems, we anticipate that using SDR will become routine in assessing tissue optical properties.

Empirical study of value effect of enterprises’ space M&A in the new normal background in China

Space M&A based on industrial concentration and pursuing concentration rent and spillover effect in new normal has become an important method to realize industrial up-grading, and how to evaluate value effect of space M&A with two-stage production system becomes a new project that has yet to be studies in academia. The article builds a M&A value evaluation simulation model based on DEA non-cooperation game to evaluate value effect of space M&A in financial industry in China.it shows, Space M&A with hypotactic game relationship can bring about substantial potential cost saving, and there must be system M&A valid when all subsystems are M&A valid. Optimal input-output index and optimal value index of intermediate variables based on model calculation further helps to obtain the measure of space M&A value improvement, which provides commercial banks with immediate empirical evidences to select M&A under new normal, helps to facilitate optimization of financial resources space configuration, and promotes transformation and upgrading as well as innovative driving of financial industry in China.

Pricing decisions during the FIFA 2014 World Cup: São Paulo and Rio de Janeiro

Purpose: This report explores the host destination’s response to the 2014 FIFA World Cup. The study establishes how the hotel Key Performance Indicators (KPIs) of two of the main cities in Brazil reacted to the World Cup. Originality/value: Exploring Brazilian hotel revenue managers’ responses to a major sporting event in Latin America is the main contribution of this research report. Relevance of the topic: Several business sectors in the travel and hospitality industry experience distinctive positive and negative performance for hosting mega-sporting events. The findings of this research report will be helpful for hotel revenue managers who regularly propose strategic pricing strategies. This report examines the response to the 2014 FIFA World Cup which is determined by the variance in the hotel key performance indexes: occupancy, average daily rate (ADR), revenue per available room (RevPAR), and supply. Design/methodology/approach: Using data gathered from Smith Travel Research (STR), this research report distinctly displays how two of the main Brazilian host cities (São Paulo and Rio de Janeiro) reacted to the World Cup. The obtained hotel KPIs represented annual data three years before the event and year after the event. The STR data entailed monthly hotel-level performance information, rooms revenue and rooms sold (demand) from the period of 2011-2015 containing a broad sample of Brazilian hotels in São Paulo and Rio de Janeiro. Key findings: Results of the analysis for São Paulo suggest that supply level did not increase drastically during the sporting event. However, ADR levels increased significantly during the event. Additionally, the variances in occupancy in 2014 echo with the variances in ADR in the same time, showing the elasticity of price. Results of the analysis for Rio de Janeiro suggest that supply volumes stay consistent before, during, and after the sporting event. The findings suggest that ADR and RevPAR were quite related, with notable increases and declines before and after the event during the comparable months in previous years. Implications for practice and policy: Our findings contained expected and unexpected results for hotel managers. For instance, Rio de Janeiro experienced growth of hotel room supply during the mega event. For this city, the drastic increase in ADR and supply did not result in a sharp decrease of their hotel occupancy rate. Other results suggest that São Paulo did not experience any changes in their hotel room supply level during the event. The performance of the occupancy rate still shows differences. For São Paulo, although there is no supply increase of the hotel industry, the occupancy rate still dropped during the mega event. This report lends support to the theory of price inelasticity of demand during mega sporting events, such as the FIFA World Cup.

Species at Risk (SPEAR) index indicates effects of insecticides on stream invertebrate communities in soy production regions of the Argentine Pampas.

We investigated relationships among insecticides and aquatic invertebrate communities in 22 streams of two soy production regions of the Argentine Pampas over three growing seasons. Chlorpyrifos, endosulfan, cypermethrin, and lambda-cyhalothrin were the insecticides most frequently detected in stream sediments. The Species at Risk (SPEAR) pesticide bioassessment index (SPEARpesticides) was adapted and applied to evaluate relationships between sediment insecticide toxic units (TUs) and invertebrate communities associated with both benthic habitats and emergent vegetation habitats. SPEARpesticides was the only response metric that was significantly correlated with total insecticide TU values for all three averaged data sets, consistently showing a trend of decreasing values with increasing TU values (r2=0.35 to 0.42, p-value=0.001 to 0.03). Although pyrethroids were the insecticides that contributed the highest TU values, toxicity calculated based on all insecticides was better at predicting changes in invertebrate communities than toxicity of pyrethroids alone. Crustaceans, particularly the amphipod Hyalella spp., which are relatively sensitive to pesticides, played a large role in the performance of SPEARpesticides, and the relative abundance of all crustaceans also showed a significant decreasing trend with increasing insecticide TUs for two of three data sets (r2=0.30 to 0.57, p-value=0.003 to 0.04) examined. For all data sets, total insecticide TU was the most important variable in explaining variance in the SPEARpesticides index. The present study was the first application of the SPEAR index in South America, and the first one to use it to evaluate effects of pesticides on invertebrate communities associated with aquatic vegetation. Although the SPEAR index was developed in Europe, it performed well in the Argentine Pampas with only minor modifications, and would likely improve in performance as more data are obtained on traits of South American taxa, such as pesticide sensitivity and generation time.

Sequential monitoring of the tail behavior of dependent data

We construct a sequential monitoring procedure for changes in the tail index and extreme quantiles of β-mixing random variables, which can be based on a large class of tail index estimators. The assumptions on the data are general enough to be satisfied in a wide range of applications. In a simulation study empirical sizes and power of the proposed tests are studied for linear and non-linear time series. Finally, we use our results to monitor Bank of America stock log-losses from 2007 to 2012 and detect changes in extreme quantiles without an accompanying detection of a tail index break.

Association of HFE gene mutations with nonalcoholic fatty liver disease in the Iranian population.

To determine whether the HFE gene variants H63D and C282Y are associated with NAFLD in persons with type 2 diabetes, we conducted a case-control study including 145 case of NAFLD patients with a history of type 2 diabetes and 145 matching control. The genomic DNA was extracted from the peripheral venous blood and the genotyping of HFE gene mutations was analyzed using the PCR-RFLP technique. Statistical analysis was performed using SPSS 12.0 software by χ2 test, t test and ANOVA (P<0.05). Data showed no increased frequency of HFE mutations in persons with type 2 diabetes and no association between H63D mutation and NAFLD in the study population. Also, we analyzed index of physiological variables including FBS, lipid profile (TC, TG, LDL-C, and HDL-C), BMI, HbA1c, and micro albuminuria and Cr levels). Data showed there are no relationship between these indexes and HFE gene mutations and either NAFLD as a complication of diabetes. But our results showed a relationship between C282Y mutation and NAFLD in persons with type 2 diabetes. C282Y mutation might be a genetic marker of NAFLD in Iranian population.

The Predictive Role of Early Trauma Dimensions on Self-Esteem in 11 - 13- Year-Old Students: Controlling the Role of Maladaptive Schema

Abstract Background: Self-esteemis a stable sense of personalworthiness. There is insufficient evidence fromthe available research to fully determine the relationship between self-esteemand early trauma. Objectives: This is a correlational study aims to investigate the relationship between early traumas as a predictor of negative self- esteemby controlling the effect of maladaptive schemas in 11-13 year-old-student sample. Methods: 292 people (201 females, 91 males) with mean age of 12.33 were selected via multistage random sampling. Participants completed questionnaire on children’s depression inventory (CDI), childhood trauma questionnaire (CTQ), schema inventory for children (SIC) and provided demographic information. Analyzing data was done using correlation and stepwise regressionmeth- ods. Results: The results showed that emotional neglect and physical abuse are the best predictors of negative self-esteem. Additionally, the results revealedno evidence ofmaladaptive schemasmediating the relationshipbetweenearly trauma andnegative self-esteem. Conclusions: In general, the findings showed that emotional neglect and physical abuse are the best predictors of negative self- esteemin children and explain a considerable variance of survival index. Our findings also demonstrate thatmaladaptive schemas do not have any significant effect on the relationship between trauma and negative self-esteem.

Preparing Teachers to Use GIS: The Impact of a Hybrid Professional Development Program on Teachers’ Use of GIS

This article reports the findings of a 3-year study of a hybrid professional development program designed to prepare science and mathematics teachers to implement GIS in their classrooms. The study was conducted as part of the CoastLines Innovative Technology Experiences for Students and Teachers project funded by the National Science Foundation. Three cohorts of teachers participated in the program, with each participant receiving 40 h of synchronous online instruction and 80 h of in-person instruction and support over an 8-month period. Data from surveys of participants both before and after the program were analyzed using correlation, ordinary least squares, and ordered logit regression analyses. The analyses revealed increases in the self-reported frequency of GIS use and enhanced feelings of preparation, competence, community, and comfort with respect to using GIS for instruction. A composite index of all impact variables was positively influenced as well. The statistical analyses found a strong relationship between self-reported feelings of preparation and use of GIS. Some support was found for the idea that feelings of competence, community, and comfort were related to the teachers’ sense of preparation. The findings suggest that a robust hybrid model of teacher professional development can prepare teachers to use GIS in their classrooms. More research is needed to understand how hybrid models influence the sociopsychological and other dimensions that support teachers’ feelings of preparation to implement GIS.

Prognostic significance of on-treatment home and clinic blood pressure for predicting cardiovascular events in hypertensive patients in the HONEST study.

We investigated the prognostic significance of morning home SBP (MHSBP) and clinic SBP (CSBP) at baseline and during follow-up in on-treatment hypertensive patients. In the Home blood pressure measurement with Olmesartan Naive patients to Establish Standard Target blood pressure study, more than 20 000 Japanese hypertensive patients who started treatment with olmesartan were followed for cardiovascular events for 2 years. MHSBP and CSBP measured at baseline and during follow-up were compared in terms of the prognostic significance in predicting cardiovascular events. The analysis included 21 591 patients (50.6% female; average age 64.9 years; mean follow-up 2.02 years; and 280 cardiovascular events). The mean MHSBP and CSBP were 151.2 and 153.6 mmHg at baseline and 135.2 and 135.2 mmHg during follow-up. Hazard ratios per 1 mmHg increase were 1.011 (95% confidence interval 1.004-1.019) and 1.006 (1.000-1.012) at baseline, and 1.039 (1.029-1.049) and 1.026 (1.016-1.036) during follow-up. When MHSBP and CSBP at baseline and during follow-up were included in the same model, only MHSBP during follow-up was identified as a significant predictive factor. The concordance index of all blood pressure variables showed reasonable discrimination abilities, and that of mean during follow-up were higher than that of SBP at baseline. The results of net reclassification improvement analyses showed that follow-up MHSBP had better reclassification ability than follow-up CSBP. SBP during follow-up (as compared with SBP at baseline), particularly MHSBP (as compared with CSBP), had better prognostic significance in predicting cardiovascular events in Japanese hypertensive patients during a 2-year clinical study.

Effects of Model Spatial Resolution on Ecohydrologic Predictions and Their Sensitivity to Inter-Annual Climate Variability

The effect of fine-scale topographic variability on model estimates of ecohydrologic responses to climate variability in California’s Sierra Nevada watersheds has not been adequately quantified and may be important for supporting reliable climate-impact assessments. This study tested the effect of digital elevation model (DEM) resolution on model accuracy and estimates of the sensitivity of ecohydrologic responses to inter-annual climate variability. The Regional Hydro-Ecologic Simulation System (RHESSys) was applied to eight headwater, high-elevation watersheds located in the Kings River drainage basin. Each watershed was calibrated with measured snow depth (or snow water equivalent) and daily streamflow. Modeled streamflow estimates were sensitive to DEM resolution, even with resolution-specific calibration of soil drainage parameters. For model resolutions coarser than 10 m, the accuracy of streamflow estimates largely decreased. Reduced model accuracy was related to the reduction in spatial variance of a topographic wetness index with coarser DEM resolutions. This study also found that among the long-term average ecohydrologic estimates, summer flow estimates were the most sensitive to DEM resolution, and coarser resolution models overestimated the climatic sensitivity for evapotranspiration and net primary productivity. Therefore, accounting for fine-scale topographic variability in ecohydrologic modeling may be necessary for reliably assessing climate change effects on lower-order Sierra Nevada watersheds (≤2.3 km2).

Exploring the Long-run and Short-run Relationship between Macroeconomic Variables and Stock Prices during the Restructuring Period: Does it Matter in Turkish Market?

This paper empirically investigated the dynamic relationship between Turkish stock market and macroeconomic variables, for the period span from January 2002 to December 2013. Specifically, we examined the effect of monetary policy changes during the tested period. Dummy variables were added to the model in order to overcome the effect of inflation rate targeting and exchange rate regime change in Turkey. Using VAR model, the result revealed that long-run relationship between share price index and the tested macroeconomic variables index of industrial production (IIP) Short-term interest rate (SINT), money supply (M2), and exchange rate (EXC), was maintained. Moreover, the findings from error correction term coefficient indicated that Turkish stock market adjusted its previous disequilibrium (due to positive or negative shocks) in one period at an adjustment speed of 4.449 percent monthly.

Comparison of old and new wheat cultivars in Iran by measuring germination related traits, osmotic tolerance and ISSR diversity.

A primary concern of modern plant breeding is that genetic diversity has decreased during the past century. This study set out to explore changes in genetic variation during 84years of breeding by investigating the germination-related traits, inter-simple sequence repeat (ISSR) fingerprinting and osmotic stress tolerance of 30 Iranian wheat (Triticum aestivum L.) cultivars. Seeds were planted under control and osmotic stress (-2, -4 and -6bar) in three replications. The ISSR experiment was carried out using 32 different primers. Genotypes were divided into two groups (old and new) each containing 15 members. The results of ANOVA showed that highly significant differences existed among genotypes and among growth conditions. The results showed that during breeding in some traits such as coleoptile length and seedling vigor index, a significant decrease has been occurred. New cultivars had a mean coleoptile length of 33mm, shorter than that of old cultivars (42mm) under osmotic stress of -6bar. Genetic variance of root length, shoot length and seedling vigor index for old cultivars were 1.59, 1.93 and 45,763, respectively, significantly higher than those for new cultivars (0.55, 1.08 and 27,996, respectively). This difference was also verified by ISSR results as the polymorphism information content was 0.28 in old cultivars, higher than that of new cultivars (0.26). These results prove this claim that during breeding, genetic diversity has decreased for many germination-related traits and breeders are better to pay more attention to genetic diversity.

개인 건강행태 및 지역보건의료 수준과 치료순응의 관계: 지역사회 건강조사 바탕으로

연구목적: 본 연구는 의사로부터 고혈압으로 진단받은 사람들을 대상으로 개인 건강행태 및 지역 보건의료수준이 치료순응에 미치는 영향을 파악하고자 실시하였다. 고혈압 치료순응은 고혈압 약물치료율로 조작적 정의를 하였다. 정의는 의사에게 고혈압을 진단받은 30세 이상 사람 중 현재 혈압 조절약을 한 달(30일)에 20일 이상 복용하고 있는 사람의 분율로 정의하였다. 연구방법: 2010년도 지역사회건강조사대상 만 19세 이상 성인 229,229명을 대상으로 개인특성에 따른 고혈압 치료순응지표의 차이 비교는 카이제곱 검정을 사용하였으며, 개인 및 지역수준 변수를 고려한 고혈압 치료순응의 관련지표의 지역 간 변이 파악은 다수준 로지스틱회귀분석 실시하였다. 통계 프로그램은 SPSS 18.0과 HLM 7(hierarchical linear model)을 이용하였다. 연구결과: 개인 건강행태 및 지역 보건의료수준이 고혈압 치료순응에 미치는 관련성 연구에서 건강행태 및 지역의 보건의료수준에 따라, 치료순응에 미치는 영향이 크다는 것을 알 수 있었다. 결론: 본 연구에서는 지역보건의료 수준의 변수들의 교차비가 높지는 않았지만, 개인수준의 변이에 초점을 맞춘 기존연구와는 달리 지역보건의료수준의 변이를 찾을 수 있었다는데 의의가 있었으며, 추후 많은 연구에서 지역수준을 고려한 다수준 분석이 필요할 것으로 사료된다. Objective: This study was conducted in order to investigate the effects of individual patient behavior regarding the health and medical care level on their therapeutic compliance for people diagnosed with high blood pressure by a physician, in order to evaluate the impact of treatment compliance. In this study, the therapeutic compliance was defined as the hypertension drug cure rate. The current blood pressure controls were persons about 30 years of age diagnosed with high blood pressure by their doctor one month fraction of the people who take more than 20 days (30 days). Methods: The data was analyzed by using the X2-test for different comparisons of the therapeutic compliance in the individual characteristics and using a two-stage multilevel logistic regression to identify the community variance of the related index of high blood pressure therapeutic compliance using the data from 229 adults over the age of 19 in a community health survey conducted in 2010. The Spss 18.0 statistical program was used with HLM 7 (hierarchical linear model) Results: It was found that the rate of therapeutic compliance was affected by the individual health behavior and health and medical care levels. Conclusion: In this study, although the odds ratio of the variable region of the high level of health care, I was able Unlike previous studies and focuses on the personal level of variation found variations in the local health care level was a significant. More studies on multilevel analysis are needed in the future considering regional level data.

Ensayo clínico cruzado y aleatorizado para comparar 2 modelos farmacocinéticos de propofol usando índices de entropía

IntroductionThere are two different pharmacokinetic models (Marsh and Schnider) for the administration of total intravenous anesthesia with propofol, the parameter differences could have some impact over the depth of anesthesia. Objectiveto determine if there is a significant difference in the variability of depth of anesthesia suggesting that one model is superior in achieving a more stable and predictable depth of anesthesia during surgery. Methodsa cross-over clinical trial was conducted on 16 healthy patients programmed for upper or lower limb ambulatory orthopedic surgery. Patients were randomly assigned to i) effect site target controlled infusion of propofol with Marsh model at a target concentration of 2,5μg/ml for 20minutes, a 20minute washout, then propofol was administered with Schnider model at the same effect site target for the reminder of the surgery, or ii) the reverse sequence. Differences in variability of depth of anesthesia, were assessed by comparing records of spectral entropy indices during surgery through an unpaired t-test. Resultsthere was no evidence of significant difference in the mean variances of either spectral entropy indices between the two models (P-value: 0.57 for State Entropy, P-value: 0.51 for Response Entropy). Conclusionthe study suggests that both pharmacokinetic models are equivalent in terms of stability of depth of anesthesia. It is important to keep testing determinants of the efficacy of the models in different types of population because their behavior according to individual characteristics of patients or variables such as cost-effectiveness could end up tilting the scale.

Randomized cross-over clinical trial comparing two pharmacokinetic models of propofol using entropy indices

IntroductionThere are two different pharmacokinetic models (Marsh and Schnider) for the administration of total intravenous anesthesia with propofol, the parameter differences could have some impact over the depth of anesthesia. ObjectiveTo determine if there is a significant difference in the variability of depth of anesthesia suggesting that one model is superior in achieving a more stable and predictable depth of anesthesia during surgery. MethodsA cross-over clinical trial was conducted on 16 healthy patients programmed for upper or lower limb ambulatory orthopedic surgery. Patients were randomly assigned to (i) effect site target controlled infusion of propofol with Marsh model at a target concentration of 2.5μg/ml for 20min, a 20min washout, then propofol was administered with Schnider model at the same effect site target for the reminder of the surgery, or (ii) the reverse sequence. Differences in variability of depth of anesthesia, were assessed by comparing records of spectral entropy indices during surgery through an unpaired t-test. ResultsThere was no evidence of significant difference in the mean variances of either spectral entropy indices between the two models (p-value: 0.57 for State Entropy, p-value: 0.51 for Response Entropy). ConclusionThe study suggests that both pharmacokinetic models are equivalent in terms of stability of depth of anesthesia. It is important to keep testing determinants of the efficacy of the models in different types of population because their behavior according to individual characteristics of patients or variables such as cost-effectiveness could end up tilting the scale.

RESEARCH IMPACTS ON ENERGY PERFORMANCE ELECTROMECHANICAL SYSTEMS

The paper analyzes the factors influencing the energy efficiency of electromechanical systems: quality voltage mode load operating conditions; quality manufacturing, maintenance and repair; active and quality construction materials. The critical effect in actual use causes the quality of the supply voltage and load mode. Using mathematical modeling showed that the variances of quality indices of electricity, exceeding the normalized standard value, normal operation of electromechanical systems, or even impossible, or may be provided only significant decrease in load. A significant reduction in energy electromechanical systems occurs even when the quality of electricity vary within the permissible standard values.