Comprehensive Cross-Efficiency Methods with Common Weight Restrictions in Data Envelopment Analysis

Considering both self-evaluation and peer evaluation, the traditional data envelopment analysis (DEA) cross-efficiency method has been widely used to evaluate efficiency scores. However, it has several defects such as excessive weight flexibility, unstable evaluation, and aggregation irrationality. This paper proposes a novel comprehensive DEA cross-efficiency method where two novel weight restriction methods are used to enhance the stability and feasibility of evaluation. Then, final efficiency scores were calculated through the geometric mean aggregation method. Finally, an empirical example is used to demonstrate that the proposed methods are more reasonable and scientific.

Aircraft Takeoff Performance in a Changing Climate for Canadian Airports

Temperature and wind are major meteorological factors that affect the takeoff and landing performance of aircraft. Warmer temperatures and the associated decrease in air density in future climate, and changes to crosswind and tailwind, can potentially impact aircraft performance. This study evaluates projected changes to aircraft takeoff performance, in terms of weight restriction days and strong tailwind and crosswind occurrences, for 13 major airports across Canada, for three categories of aircraft used for long-, medium- and short-haul flights. To this end, two five-member ensembles of transient climate change simulations performed with a regional climate model, for Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios, respectively, are analyzed. Results suggest that the projected increases in weight restriction days associated with the increases in daily maximum temperatures vary with aircraft category and airfield location, with larger increases noted for airfields in the south central regions of Canada. Although avoiding takeoff during the warmest period of the day could be a potential solution, analysis focused on the warmest and coolest periods of the day suggests more weight restriction hours even during the coolest period of the day, for these airfields. Though RCP8.5 in general suggests larger changes to weight restriction hours compared to RCP4.5, the differences between the two scenarios are more prominent for the coolest part of the day, as projected changes to daily minimum temperatures occur at a much faster rate for RCP8.5 compared to RCP4.5, and also due to the higher increases in daily minimum temperatures compared to maximum temperatures. Both increases and decreases to crosswind and tailwind are projected, which suggest the need for detailed case studies, especially for those airfields that suggest increases. This study provides useful preliminary insights related to aircraft performance in a warmer climate, which will be beneficial to the aviation sector in developing additional analysis and to support climate change adaptation-related decision-making.

THE OPTIMIZATION OF THE METHOD FOR SYNTHESIS OF HYDROTREATING CATALYSTS

Nowadays the standards for sulfur content in different countries provide for a significant reduction of the indicator to 10 ppm for the gasoline- the raw material for catalytic reforming and 0,01% by weight. Restriction of the total content of aromatic hydrocarbon (no more than 20%), replaced by standards of polycyclic aromatic hydrocarbons (no more than 6-10%) and cetane number (45 and higher). This article outlines the development of optimization of the method for synthesis of hydrotreating catalysts. The main purpose of this article is consideration, mainly by the composition of the developed catalyst, of the ways of their modification by additional components, changing the number of active components, modification of the porous structure of the carrier through the synthesis of special types of aluminum oxide with a specified pore distribution by radius or inserting the zeolite component, changes in the conditions of thermal activation of catalysts. One of the main trends in the development of hydrotreating catalysts is their modification by different additives, for example: phosphorus, alkali element, zinc, tin, germanium, copper, uranium, etc. KEYWORDS: activity of industrial catalyst, impregnation by solutions, carrier modification, dispersion of nickel on aluminum oxide.

Secular trends in adiposity and musculoskeletal dimensions of elite heavyweight boxers between 1889 and 2019

Purpose With improving nutrition and health, athletes have grown taller and heavier over the past century. Since there is no weight restriction in the heavyweight class, secular changes in anthropometric measurements of heavyweight boxers may mirror those of contemporary general populations. Objectives We aimed to (1) examine secular trends in adiposity and musculoskeletal measurements in heavyweight boxers, (2) determine anthropometric differences between champions and unsuccessful challengers. Methods Detailed demographics taken at time of contest (first official World Championship to current contest: 1889–2019) were collected from media archives. Results All 237 boxers (83 champions, 154 challengers) contesting a recognised heavyweight World Championships were identified. They had mean (± SD) age = 28.9 ± 4.1 years, height = 187.3 ± 6.5 cm, reach = 195.2 ± 9.4 cm, weight = 97.5 ± 11.5 kg, BMI = 27.8 ± 2.4 kg/m2 and waist = 87.9 ± 6.2 cm. Contest years explained 25.9% (p < 0.001) of the variance in BMI for champions and 30.9% (p < 0.001) for challengers, 9.1% (p < 0.071) in WC for champions and 19.9% (p < 0.001) for challengers. Contest years correlated with height (r = 0.531, p < 0.001), reach (r = 0.341, p < 0.001), weight (r = 0.603, p < 0.001) and BMI (r = 0.370, p = 0.001) among all documented boxers, and with waist only in challengers (r = 0.349, p < 0.001) but not in champions (r = 0.078, p = 0.509). Compared with challengers, champions had greater stature by + 3.4 cm (p < 0.001), reach + 3.6 cm (p = 0.005) and weight + 3.7 kg (p = 0.017), with similar BMI and waist. Champions had larger biceps and forearms but did not differ from challengers in other musculoskeletal dimensions. Conclusions Over 130 years elite heavyweight boxers have increased in size (BMI) and reach but waists in champions have remained static. Being heavier, taller with longer and bigger arms, but with similar in BMI and waist, appear to be differentiating factors between champions and challengers.

Supplier selection considering sustainability measures: an application of weight restriction fuzzy-DEA approach

With the growing of consumer awareness in environmental and social issues sustainable development has become an essential element in supply chain management. Supplier evaluation and selection is one of the main strategic decisions for purchasing management in supply chain. This paper use Data Envelopment Analysis (DEA) to propose a new model for evaluation and ranking of a given set of suppliers from sustainable point of view. The proposed model integrates the fuzzy set theory and DEA to consider the decision makers’ preferences and handle the ambiguity and uncertainty in supplier selection process. For this purpose, linguistic values in the form of triangular fuzzy numbers are used to assess the weights of criteria, sub-criteria, and the ratings of suppliers’ performance with respect to sub-criteria. Then, a fuzzy-DEA model, using α-cut approach, is developed considering weight constraints. An application from Supplying Automotive Parts Company (SAPCO) Company, which is one of the largest suppliers of automotive parts in the Middle-East, is presented to show the applicability of the proposed model. Finally, the proposed weight restriction fuzzy-DEA model is validated through comparing with one of the recent supplier selection methods.

Translation and Cross-Cultural Adaptation of a Brazilian Version of the Child Feeding Questionnaire

The Child Feeding Questionnaire (CFQ) assesses parental attitudes, beliefs and practices about child feeding and obesity proneness. This research aimed to translate and to test the reliability of the CFQ and to evaluate this instrument in Brazilian families. The participants were 300 mothers and 300 children, aging from 2 to 11 years old, of both sexes. The translation, synthesis, back-translation, evaluation by an expert committee and pre-test were performed. Besides the application of questionnaire to mothers, data regarding anthropometric measurements in mothers and children was collected. The indexes of content validity index, test-retest reliability and internal consistencies were good. The parental factors Perceived parent weight, Perceived child weight, Concern about child weight, Restriction, Pressure to eat and Monitoring on child feeding were associated with overweight in childhood. In conclusion, these results highlight the validity and utility of the Brazilian version of the CFQ.