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2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rita Shakouri ◽  
Maziar Salahi

Purpose This paper aims to apply a new approach for resource sharing and efficiency estimation of subunits in the presence of non-discretionary factors and partial impacts among inputs and outputs in the data envelopment analysis (DEA) framework. Design/methodology/approach First, inspired by the Imanirad et al.’s model (2013), the authors consider that each decision-making unit (DMU) may consist of several subunits, that each of which can be affected by non-discretionary inputs. After that, the Banker and Morey’s model (1996) is used for modeling non-discretionary factors. For measuring performance of several subunits, which can be considered as DMUs, the aggregate efficiency is suggested. At last, the overall efficiency is computed and compared with each other. Findings One of the important features of proposed model is that each output in this model applies discretionary input according to its need; therefore, the result of this study will make it easier for the managers to make better decisions. Also, it indicates that significant predictions of the development of the overall efficiency of DMUs can be based on observing the development level of subunits because of the influence of non-discretionary input. Therefore, the proposed model provides a more reasonable and encompassing measure of performance in participating non-discretionary and discretionary inputs to better efficiency. An application of the proposed model for gaining efficiency of 17 road patrols is provided. Research limitations/implications More non-discretionary and discretionary inputs can be taken into consideration for a better analysis. This study provides us with a framework for performance measures along with useful managerial insights. Focusing upon the right scope of operations may help out the management in improving their overall efficiency and performance. In the recent highway maintenance management systems, the environmental differences exist among patrols and other geotechnical services under the climate diverse. Further, in some cases, there might exist more than one non-discretionary factor that can have different effects on the subunits’ performance. Practical implications The purpose of this paper was to measure the performance of a set of the roadway maintenance crews and to analyze the impact of non-discretionary inputs on the efficiency of the roadway maintenance. The application of the proposed model, on the one hand, showed that each output in this model uses discretionary input according to its requirement, and on the other hand, the result showed that meaningful predictions of the development of the overall efficiency of DMUs can be based on observing the development level of subunits because of the impact of non-discretionary input. Originality/value Providing information on resource sharing by taking into account non-discretionary factors for each subunit can help managers to make better decisions to increase the efficiency.


2021 ◽  
Vol 44 (6) ◽  
pp. 20200207
Author(s):  
Cristiana Ferreira ◽  
Fredy Díaz-Durán ◽  
Antonio Viana da Fonseca ◽  
Giovanni Cascante
Keyword(s):  

2021 ◽  
Author(s):  
Vladimir Y. Gotsulsky ◽  
Salvatore Magazù ◽  
Nikolay P. Malomuzh

Abstract A new approach to the physical nature of the water density maximum at 4°C is proposed. The main attention is focused on the role of H-bonds in the formation of the specific volume and thermal expansion coefficients for ordinary and heavy water. It is shown that the minimum of the specific volume for water is connected with the amplification of H-bonds (D-bonds) role at approaching their triple points.


2021 ◽  
pp. 1-7
Author(s):  
Tetiana Kovalchuk ◽  
Oksana Boyarchuk

Abstract Background: Recent studies confirm the role of B vitamins deficiency and hyperhomocysteinaemia in the development of dysautonomia that has been considered to be the main factor in vasovagal syncope development. The aim of the study was to investigate serum pyridoxine, folate, cobalamin, and homocysteine levels in children presenting with vasovagal syncope and to analyse the correlation between them and main clinical parameters of syncope. Methods: We studied 40 children, ages 8–17 years with a history of vasovagal syncope and 24 healthy volunteers. The serum pyridoxine, folate, cobalamin, and homocysteine levels were measured by a quantitative sandwich enzyme immunoassay technique using a commercial kit (Monobind, USA). Twenty-four-hour Holter monitoring and 24-hour ambulatory blood pressure monitoring were conducted for all participated patients. Results: Serum pyridoxine (9.42 ± 4.87, 16.11 ± 5.53 µg/L) and cobalamin (307.48 ± 95.50, 447.28 ± 108.85 ng/L) levels were reasonably low (p < 0.05) in patients with vasovagal syncope. Although there was no significant change in folate levels between syncope and healthy children (4.00 ± 1.34, 4.71 ± 1.73 µg/L; p = 0.20), we detected low folate-level association with longer duration of syncope (r = −0.42) and post syncope (r = −0.43) symptoms (p < 0.05). Finally, there was increased serum homocysteine level (13.55 ± 5.03, 7.81 ± 1.71 µmol/L; p < 0.05) in patients with vasovagal syncope. It was positively correlated with the average PQ interval (r = 0.35, p < 0.05) and average QTc interval (r = 0.49, p < 0.05). Conclusions: The results suggested that pyridoxine, folate, cobalamin, and homocysteine may be involved in the pathogenesis of vasovagal syncope. This might provide a new approach for effective treatment of paediatric vasovagal syncope, requiring further study.


2021 ◽  
Vol 14 (3) ◽  
pp. 78
Author(s):  
Thomas Konstantinovsky ◽  
Matan Mizrachi

We propose a new approach to text semantic analysis and general corpus analysis using, as termed in this article, a &quot;bi-gram graph&quot; representation of a corpus. The different attributes derived from graph theory are measured and analyzed as unique insights or against other corpus graphs, attributes such as the graph chromatic number and the graph coloring, graph density and graph K-core. We observe a vast domain of tools and algorithms that can be developed on top of the graph representation; creating such a graph proves to be computationally cheap, and much of the heavy lifting is achieved via basic graph calculations. Furthermore, we showcase the different use-cases for the bi-gram graphs and how scalable it proves to be when dealing with large datasets.


Author(s):  
Nazim Bouatta ◽  
Peter Sorger ◽  
Mohammed AlQuraishi

The functions of most proteins result from their 3D structures, but determining their structures experimentally remains a challenge, despite steady advances in crystallography, NMR and single-particle cryoEM. Computationally predicting the structure of a protein from its primary sequence has long been a grand challenge in bioinformatics, intimately connected with understanding protein chemistry and dynamics. Recent advances in deep learning, combined with the availability of genomic data for inferring co-evolutionary patterns, provide a new approach to protein structure prediction that is complementary to longstanding physics-based approaches. The outstanding performance of AlphaFold2 in the recent Critical Assessment of protein Structure Prediction (CASP14) experiment demonstrates the remarkable power of deep learning in structure prediction. In this perspective, we focus on the key features of AlphaFold2, including its use of (i) attention mechanisms and Transformers to capture long-range dependencies, (ii) symmetry principles to facilitate reasoning over protein structures in three dimensions and (iii) end-to-end differentiability as a unifying framework for learning from protein data. The rules of protein folding are ultimately encoded in the physical principles that underpin it; to conclude, the implications of having a powerful computational model for structure prediction that does not explicitly rely on those principles are discussed.


Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 148
Author(s):  
Yongquan Wang ◽  
Guangpeng Zhang ◽  
Jiali Wang ◽  
Pan Liu ◽  
Nina Wang

The reconfigurable manufacturing system (RMS) is a new manufacturing technology and paradigm that resolves the contradictions regarding high efficiency, low cost and flexible production in the mass production of part families. Reconfigurable machine tools (RMTs) are the core components of RMSs. A new approach is proposed for the design of RMTs, which is closely related to the process planning of a given box-type part family. The concepts of the processing unit and the processing segment are presented; they are not only the basic elements of the processing plans of machined parts, but also closely related to the structural design of RMTs. Processing units created by processing features can be combined into various processing segments. All the processing units of one processing segment correspond to the machining operations performed by one RMT. By arranging the processing segments according to the processing sequence, a variety of feasible processing plans for a part can be obtained. Through analysis of the established similarity calculation model for processing plans, the most similar processing plans for the parts in a given part family can be determined and used for the structural design of RMTs. Therefore, the designed RMTs can achieve rapid conversion of processing functions with the least module replacement or adjustment to realize the production of the parts in the part family. Taking the production of a gearbox part family as an example, the validity of the presented method is verified.


2021 ◽  
Vol 9 ◽  
Author(s):  
Pengfei Wu ◽  
Senchi Yang ◽  
Yingying Ren ◽  
Hongliang Liu

We report on the fabrication of waveguides and beam splitters in pure YAG crystals by femtosecond laser direct writing (FLDW). During the femtosecond laser writing process, a positive refractive index is induced through the nonlinear focusing above the focus position, resulting in an unusual guiding cross-sectional configuration. The supported guiding modes at 632.8 nm are measured and analyzed using the end–face coupling system. The propagation loss can be as low as 1.9 dB/cm for the single-line waveguide. Different from the geometry of the traditional fs-laser modified area, this novel structure might offer a new approach in the quest toward integrated photonics.


2021 ◽  
Vol 11 (15) ◽  
pp. 7005
Author(s):  
G A Pablo Cirrone ◽  
Nino Amato ◽  
Roberto Catalano ◽  
Alessandro Di Domenico ◽  
Giacomo Cuttone ◽  
...  

This paper describes a new real-time, in vivo, noninvasive, biasless detector system acting as a beam monitoring and relative dose measurement system. The detector is based on the idea that when a beam current is injected into the body of a patient undergoing a charged particle therapy, the current itself can be collected using a conductive electrode in contact with the patient’s skin. This new approach was studied in vitro using an electrically isolated water tank irradiated with monoenergetic proton beams. The conductive electrode was immersed in water and positioned outside the irradiation field. The detection system performance was evaluated by comparing its response against a SEM (Secondary Emission Monitor) detector, used as a reference beam current monitor, and an Advanced Markus ionization chamber. Short-, mid- and long-term reproducibility, current monitoring capability, field size dependence, electrode position and environment temperature dependence, linearity with dose, and dose rate dependence were investigated. Few preliminary in vivo tests were also performed that demonstrated the possibility to apply the system in clinical practice. The potential of the proposed method is considerable, representing a simple and economical system for online, in vivo, and noninvasive monitoring of the beam current and relative released dose into the patient during treatment, without perturbing the irradiation field. The system presented in this work is protected with both a National Italian (N. 102017000087851) and an International N. WO 2019/025933 patent.


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