Introduction a method of determining returns to scale in network data envelopment analysis

In the process of evaluating the Decision Making Units, two factors of efficiency and production size can be used. When the production size of a unit is not optimal, its Returns To Scale (RTS) determines that changing the resources in anotherdirection would enhance its productivity. In most previous research, RTS is considered to be increasing or decreasing, and frontier analysis is used to determine it. The concept of RTS in Network Data Envelopment Analysis (DEA) is so interesting. In this paper a method based on Most Productive Scale Size (MPSS) in several steps is developed, in addition to determining that RTS of units for each unit in directional manner, the shortest changes in resources for achieving the right size for network production is also obtained. In this approach, the computational complexity, and the ambiguity in units RTS is not present

Triiodothyronine Mitigates Cardiac Dysfunction in Aluminum Phosphide Poisoning: Findings from a Randomized Clinical Trial

Introduction: Aluminum phosphide (AlP) poisoning, commonly known as rice tablet poisoning, is a lethal method of suicide with no known antidotes. Thyroid hormones have inotropic effects that can potentially reverse hemodynamic instability and improve cardiac output. This study investigated the effects of Triiodothyronine (T3) on the cardiac function of patients with aluminum phosphide poisoning.Methods: In this randomized clinical trial, 24 patients with confirmed ALP poisoning were recruited. The intervention group received T3 treatment in addition to standard treatment, while the control group received only standard treatment. Demographic variables, cardiac parameters, biochemical markers, and oxidative stress tests were evaluated.Results: The majority of participants were men (60%) in their thirties (intervention: 32±17.4 years; control: 30±11.6 years). Following treatment, both systolic and diastolic blood pressures had significantly higher mean differences in the T3 group compared to the control group (18.7±9.3, P=0.05 and 14.1±5.9, P=0.03 respectively). While both groups showed improvement in mean arterial pH, the intervention group exhibited a significantly greater improvement 12 hours after the administration of T3, which was significantly different from both the baseline and control groups (p=0.04, 0.009 respectively). Additionally, the intervention group had a lower QRS and QTc interval compared to admission time.Conclusion: Triiodothyronine administration has been shown to maintain a higher range of SBP, control cardiogenic shock, regulate metabolism, improve acidosis and blood pressure, and ultimately enhance recovery in patients with aluminum phosphide poisoning. Furthermore, it may have cardio-protective effects on these patients

Carbon efficiency evaluation:an analytical framework using fuzzy DEA

Data Envelopment Analysis (DEA) is a powerful analytical technique for measuring the relative efficiency of alternatives based on their inputs and outputs. The alternatives can be in the form of countries who attempt to enhance their productivity and environmental efficiencies concurrently. However, when desirable outputs such as productivity increases, undesirable outputs increase as well (e.g. carbon emissions), thus making the performance evaluation questionable. In addition, traditional environmental efficiency has been typically measured by crisp input and output (desirable and undesirable). However, the input and output data, such as CO2 emissions, in real-world evaluation problems are often imprecise or ambiguous. This paper proposes a DEA-based framework where the input and output data are characterized by symmetrical and asymmetrical fuzzy numbers. The proposed method allows the environmental evaluation to be assessed at different levels of certainty. The validity of the proposed model has been tested and its usefulness is illustrated using two numerical examples. An application of energy efficiency among 23 European Union (EU) member countries is further presented to show the applicability and efficacy of the proposed approach under asymmetric fuzzy numbers

Portfolio Selection by a Non-Radial DEA Model; Its application in Tehran Stock Exchange (TSE)

In this paper, considering risks of a portfolio such as mean return, variance of returns, and moments of higher order as output variables including desirable and undesirable outputs, we introduce a non-radial and slack based score to measure efficiency of portfolios. Using the present measure, ranking of portfolios is provided which is consistent with standard risk-return ratios in finance. We provide illustrations to show the effects of this contribution on the measures of technical efficiency and ranking of portfolios on a sample set of daily prices of banks and credit institutions listed on the first stock market of Tehran Securities Exchange (TSE). The advantage of this paper is to present a model based on stock market returns and risk, which is based on the DEA view of the production possibility set. Of course, in making it, the quadratic property of variance and the origin of coordinates have been used as a moderating point

مقایسه تأثیرات تزریق داخل پریتوئن بوپیواکائین، مرفین و دگزامتازون بر درد پس از جراحی سزارین الکتیو در بیهوشی عمومی

سابقه و هدف: درد کنترلنشده، میتواند عوارض و مرگ و میر پس از عمل سزارین را افزایش دهد. هدف از این مطالعه، مقایسه تأثیرات تزریق داخل پریتوئن بوپیواکائین، مرفین و دگزامتازون بهطور جداگانه بر کنترل درد پس از جراحی سزارین است. مواد و روشها: با استفاده از مطالعهی مداخلهای دوسوکور، 111 زن باردار 22 تا 12 سالهی کاندید سزارین الکتیو، بهطور همه بیماران، در بیهوشی عمومی با روش مشابه قرار گرفتند. در مراحل .)N= تصادفی انتخاب و به چهار گروه تقسیم شدند ) 36 11 دگزامتازون 32 سیسی رقیق mg )D( 2 درصد، در گروه دو / 32 سیسی بوپیواکائین 22 )B( پایانی جراحی، در گروه یک 32 سیسی نرمال سالین توسط جراح به )S( 2 مرفین که به 32 سیسی رقیق گردید و در گروه کنترل mg )M( شد، در گروه سه 1 و 1 ساعت پس از جراحی، درد با استفاده از مقیاس دیداری درد ، داخل پریتوئن ریخته شد. پس از عمل در فاصلههای زمانى 2 به شیوه امتیازدهی، از 2 تا 12 ثبت گردید. همچنین، میزان مصرف مسکن، علائم حیاتی، شیوع تهوع و استفراغ ثبت شد. (VAS) و با SPSS بالاتر از 3، مپریدین وریدى تجویز شد. دادهها با استفاده از نرمافزار آماری 23 VAS در دوره پس از عمل در بیماران با 2 تجزیه و تحلیل شدند. / با سطح معنیداری کمتر از 22 ،ANOVA بکارگیری آزمون 1 و 1 ساعت ، و میانگین مصرف مپریدین بین گروههای مورد مطالعه و گروه کنترل در ریکاوری، 2 VAS : یافتهها ) /22±2/12 ،2/72±2/ 1 و 1 ساعت بعد از خاتمه جراحی، گروه دگزامتازون ) 21 .(P<2/ پس از جراحی معنادار بود ) 221 2( بهترتیب، کمترین میزان درد را تجربه کردند. /23±2/22 ،2/21±2/ و بوپیواکائین ) 32 استنتاج: با توجه به نتایج حاصل از پژوهش حاضر، تزریق اینتراپریتونئال بوپیواکائین، مرفین و دگزامتازون، بهطور قابلتوجهی، درد پس از جراحی را در 1 ساعت اول بعد از جراحی سزارین، کاهش میدهد. واژههای کلیدی: بیهوشی عمومی، بوپیواکائین، مرفین، تزریق داخل پریتوئن، دگزامتازون، درد پس از جراحی، سزارین الکتی

Congestion and non-congestion areas: identify and measure congestion in DEA

Detecting the weak and strong congestion statuses of decision-making units (DMUs) and measuring them via data envelopment analysis (DEA) is an important issue that has been discussed in several studies and with different views. The efficiency frontier is a concept derived from the underlying production possibility set (PPS), and the congestion concept is related to them. Still, researchers have defined congestion for each DMU in many previous studies and ignored that congestion is linked with the underlying production technology. In the congestion measurement matter, this paper presents two new insights into a congestion area and non-congestion area for production technology and two new mathematical definitions of congestion based on the PPS properties and detecting the weak and strong congestion status of DMUs (CSOD). We prove our definitions are equal to the original definition of congestion. First, we describe the congestion and non-congestion areas based on the PPS; then provide full details of how to measure congestion built on these new insights. Our approaches are very accurate and fast to calculate; they are theoretically elementary and efficient in performance. Our proposed methods can deal with both non-negative and negative data. Finally, an empirical example is provided to illustrate our approaches

Application of Malmquist productivity index with carry-overs in power industry

Total Factor Productivity (TFP), as a main resource in providing economic development, has a significant role in increasing competitiveness because one can study the performance rate of economic and industrial sectors in optimal utilisation of productive resources through analysis and calculation of TFP indexes. In Data Envelopment Analysis (DEA), there are different methods for measuring changes in TFP of Decision Making Units (DMU) at different times using different technologies. One of the most important is the Malmquist Productivity Index (MPI). Currently, in many economic and industrial activities namely investment and energy, there are some indexes that transform during different periods (called Carry-Over) and thus affect the performance of a DMU in another period, based on the performance of a DMU in a specific time period. These indexes may vary from time to time, i.e. in one time interval they may be good and in another one they may be bad; this tends to be ignored in the traditional MPI. In this paper, we develop the MPI by considering transforming indexes using a Slack-Based Measure (SBM) model in Variable Returns to Scale (VRS). Finally, we analyse the electricity industry of Iran in two consecutive years. Keywords: Data envelopment analysis, Malmquist productivity index, Carry-over index, Electricit

A slack-based super efficiency in a two-stage network structure with intermediate measures

One of the main challenging issues in the conventional data envelopment analysis (DEA) is ranking efficient decision-making units (DMUs) when more than one DMU have the efficiency score equal to one. It must be mentioned that most of the DMUs have internal structures. In this regard, in order to measure the efficiency score of these DMUs, network DEA methods are applied. Most researches are focused on assessing the efficiency of these DMUs and just like the classic DEA, several DMUs are efficient. To identify the sources and estimate the amount of inefficiencies in DMUs with network structure and overcome some shortcomings in the previous ranking models, in this paper, a slack-based network model of super efficiency, considering the optimal value of intermediate measures in the objective function and right handset for ranking overall efficient DMUs, are suggested to have more accurate and comprehensive ranking DMUs with internal structures. Finally, two numerical and empirical examples are provided to verify the discriminative power of the proposed model. Keywords: Data envelopment analysis (DEA), Network DEA (NDEA), Slack-based measure, Super efficiency, Rankin

The effect of alfentanil on maternal haemodynamic changes due to tracheal intubation in elective caesarean sections under general anaesthesia

Background and Aims: Endotracheal intubation can produce severe maternal haemodynamic changes during caesarean sections under general anaesthesia. However, administration of narcotics before endotracheal intubation to prevent these changes may affect the Apgar score in neonates. This study was designed to evaluate the effect of intravenous alfentanil on haemodynamic changes due to endotracheal intubation in elective caesarean sections performed under general anaesthesia. Methods: Fifty parturients were randomly divided into two equal groups. Patients in the first group received alfentanil 10 μg/kg and in the second group received placebo intravenously 1 min before induction of anaesthesia for elective caesarean section. Haemodynamic parameters and bispectral index system (BIS) in mothers, peripheral capillary oxygen saturation (SpO 2 ) and Apgar score in the newborn were assessed. Results: Changes in systolic blood pressure were significant at 1, 5 and 10 min after intubation between two groups. Changes in diastolic blood pressure were significantly less in alfentanil group, 1 min after induction of anaesthesia and 1 min after endotracheal intubation. Mean heart rate at 1 min after induction and at 1 and 5 min after intubation also reduced significantly in this group. Conclusion: Alfentanil use was associated with decreases or minimal increases in maternal systolic and diastolic blood pressures and heart rate after endotracheal intubation