The field of occupational health and safety (OHS) focuses on reducing occupational accidents to an acceptable level. OHS covers systematic efforts aimed at providing employee health, safety and ...welfare in the workplace. This study proposes a new approach for risk assessment in the field of OHS. It integrates the Pythagorean fuzzy analytic hierarchy process (PFAHP) and fuzzy VlseKriterijumska Optimizacija I Kompromisno Resenje (FVIKOR) into a risk assessment process. The PFAHP is used in weighting the risk parameters. FVIKOR is then applied to prioritize the hazards. To demonstrate the applicability and validity of the proposed approach, a case study of a barrel external surface oxidation and colouring unit of a gun and rifle production facility is performed. A comparison is also provided between the proposed approach and an intuitionistic fuzzy sets-based approach. The proposed approach is found to produce reliable outcomes that better represent the vagueness of the decision-making process.
The present study deals with the development of five different brake friction composites to the standard of Indian scenario brake pads by varying the different cashew friction dusts namely furfural ...modified, boron modified, boron-graphite modified, cardanol and CNSL based without varying the other ingredients. The developed brake friction composites were tested for their physical, chemical, mechanical and thermal properties as per industrial standards. The thermal stability was found for varying ingredients and the developed composites using Thermo Gravimetric Analyser. Tribological properties were analysed using full-scale inertia brake dynamometer as per JASO-C-406 Schedule. The ranking of the dyno tested friction composites was done using VIKOR and ELECTRE methods. Scanning Electron Microscopy coupled with elemental mapping was used to elucidate back transfer and surface characteristics of the dyno tested brake pads. The results revealed that boron-graphite modified friction dust-based brake pads were beneficial with good fade, wear resistance and recovery characteristics due to its thermally stable and heat dissipating characteristics.
•Utilisation of various cashew friction dusts as an ingredient in brake pads.•Boron-graphite modified friction dust based brake pads showed lower fade & higher recovery rates.•Boron-graphite modified friction dust based brake pads showed less pad and rotor wear.
Konzumacija svježih citrusa, ali i njihova prerada generiraju nusproizvode, kao što su kora, sjemenke, pulpa, kao i otpadne vode. Cilj ovog istraživanja je valorizacija agroindustrijskih nusproizvoda ...(kore citrusa) kao vrijedne sirovine za ekstrakciju polifenola primjenom inovativne netermalne metode ekstrakcije sa zelenim otapalom (voda). U ekstraktima je kvantificirano i identificirano ukupno šest fenolnih spojeva. Pri tome je promatran utjecaj vremena (od 5 do 15 min), frekvencije (od 40 do 100 Hz) i omjera kapljevito/kruto (od 200 do 400 ml g−1) na efikasnost procesa ekstrakcije (iskorištenje) i udio dominantnih fenolnih spojeva (hesperidina i narirutina). Uz pomoć metode odzivnih površina definirani su optimalni parametri promatranog procesa ekstrakcije za svaki od istraživanih odziva, i to za iskorištenje (285,93 ml g−1, 73,38 Hz i 14,84 min), za hesperidin (366,19 ml g−1, 97,56 Hz i 5,1 min) te za narirutin (200 ml g−1, 70 Hz i 15 min). Ekstrakcija potpomognuta visokonaponskim električnim pražnjenjem (HVED ekstrakcija) pokazala se pogodnom za ekstrakciju fenolnih spojeva, pri čemu je izbjegnuta uporaba organskih otapala.
Failure mode and effects analysis (FMEA) is a widely used reliability analysis tool for identifying and eliminating known or potential failures in system, design, and process. In traditional FMEA, ...failure modes are evaluated by FMEA team members with respect to three risk factors: severity (S), occurrence (O), and detectability (D), and ranked via their risk priority number (RPN), which is obtained by multiplying the crisp values of S, O, and D. However, traditional RPN has been considerably criticized due to the following shortcomings: not considering the different weights of risk factors; the identical value of RPN for different combinations of S, O, and D; the diversity and uncertainty of evaluation information given by FMEA team members and without considering the dependence among different failure modes. Although significant efforts have been made in FMEA literatures to overcome these shortcomings, there are still some deficiencies. In this paper, a new risk priority model is presented for FMEA by using the house of reliability (HoR)-based rough VIsekriterijumska optimizacija i KOmpromisno Resenje (VIKOR) approach. In the proposed model, the HoR is introduced to identify the dependence among different failure modes and the link between failure modes and the risk factors of O, D and the subcriteria of S. Rough number is introduced to manipulate the subjectivity and vagueness in decision making and VIKOR approach is used to determine the risk priority order of failure modes in a comprehensive way. Finally, an illustrative case in transmission system of a vertical machining center has demonstrated the effectiveness and practicality of the proposed model.
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•PQC requires energy-consuming vigorous vibrations for compaction while LF-SCC renders advantages similar to that of SCC i.e. self-compaction but with lesser fines ...(350–550 kg/m3).•LF-SCC mixes with up to 50 % of RHA are found to satisfy the requirements of IRC: 44–2017 for the construction of either village roads or urban roads.•20% of RHA as cement-replacing material is found to be optimum in the production of LF-SCC.•FE-SEM and EDX analysis shows the development of more CSH gel and other strength-enhancing compounds with 20% of RHA as compared to other mixes.•An MCDM method i.e. VIKOR method is used for the optimization of the mixes.
This article presents the characteristics of low-fines self-consolidating concrete (LF-SCC) with rice husk ash (RHA) replacing cement (OPC) at 0 %, 10 %, 20 %, 30 %, 40 %, and 50 % by weight for the construction of rigid pavement. Results show that RHA up to replacement level 20 % positively improves properties of the LF-SCC, on further inclusion of RHA above 20 %, they decrease. All of the mixes' fresh properties comply with European standards. In application to pavement construction, all the six LF-SCC mixes are satisfying the required limits of 20MPa for 7 days early strength, 30 MPa to 40 MPa for 28 days’ compressive strength for rural and urban roads, respectively; and 3.8 to 4.5 MPa for 28 days’ flexural strength for rural and urban roads, respectively. The results of durability tests reveal that the mixes are less water absorbing, less permeable to water and other weathering agents. Thus, the mixes are well suitable for the construction of road pavements.
Sustainable urban renewal has received tremendous academic attention and has been put into wide practice around the world. In order to avoid unsustainable renewal projects, the evaluation of the ...sustainability of urban renewal has become a critical procedure. However, there is an insufficient number of relevant studies on ex-ante evaluation compared to a large amount of literature focusing on ex-post evaluation. Most literature does not fully consider the interdependency between the dimensions/criteria of evaluation. How to utilize this to evaluate real cases is shortage. Hence, this study presents an ex-ante decision-making model for evaluating the sustainability of urban renewal projects based on hybrid multiple-attribute decision-making (MADM) from a government perspective, and includes three classical dimensions: economic (D1), social and cultural (D2), and environment (D3), as well as 13 relevant criteria. A case in Taiwan is used to evaluate the potential performance of sustainability and explore improvement strategies. Empirical results from the Decision Making Trial and Evaluation Laboratory (DEMATEL) reveal that the social and cultural (D2) dimension impact the environment (D3) and economic (D1) dimensions, with the economic (D1) dimension being the most impacted by other dimensions. Enhancing transportation (C5), strengthening the accessibility of various public facilities (C4), preserving local culture (C9), increasing greening and open space (C10), and improving land-use efficiency (C3) are the criteria in the “cause” position, among which strengthening the accessibility of various public facilities (C4) and improving land-use efficiency (C3) are considered to be the core of urban renewal project sustainability based on DEMATEL and the DEMATEL-based analytic network process (DANP). The modified VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method indicated that the social and cultural (D2) and the environment (D3) dimensions have poor performance. Thereafter relevant improvement strategies and paths are suggested based on an influence network relation map (INRM). The results imply that recent urban renewal policy reform in Taiwan represents a step toward sustainable development.
•Exploring the interdependency between the dimension/criteria for ex-ante sustainable evaluation of urban renewal projects.•A new model of hybrid multiple-attribute decision-making is utilized.•A case in Taiwan is used to evaluate the potential of sustainability and explore improvement strategies.•Results indicate that social and cultural (D2) dimension impact the environment (D3) and economic (D1) dimensions.
Cilj rada bio je izraditi računalni program koji služi za proračun optimalnog temperaturnog profila hlađenja šaržnog kristalizatora. Kao modelni sustav za istraživanje procesa uzet je kalijev nitrat ...otopljen u vodi. Za izradu matematičkog modela procesa primijenjene su populacijske bilance, odnosno njihova momentna transformacija. Za dobivanje optimalnog temperaturnog profila primijenjena je diskretizacija temperaturnog profila uz globalni algoritam optimizacije. Za provođenje optimizacije primijenjen je genetički algoritam, dok je sustav običnih diferencijalnih jednadžbi rješavan metodom Runge-Kutta 4,5. Funkcija cilja bila je minimiziranje omjera trećeg momenta sekundarnom nukleacijom nastalih kristala i trećeg momenta kristala cjepiva na kraju procesa. U radu je najprije ispitan utjecaj uvjeta zaustavljanja genetičkog algoritma na vrijeme proračuna i vrijednost funkcije. Nakon što je određen optimalni uvjet zaustavljanja, ispitan je utjecaj broja točaka diskretizacije temperaturnog profila na iznos funkcije cilja i potrebno vrijeme proračuna. Ustanovljeno je da je optimalni uvjet za zaustavljanje proračuna kad petnaest članova generacije imaju funkcije cilja koje se ne razlikuju više od tolerancije. Ustanovljeno je da se optimalno rješenje dobiva podjelom temperaturnog profila na osam dijelova. Da bi se ispitala ponovljivost proračuna za optimalne uvjete, proračun je ponavljan devet puta. Optimalni temperaturni profil uspoređen je s linearnim hlađenjem istog trajanja. Rezultati simulacijskih eksperimenata ukazuju na znatno poboljšanje procesa primjenom optimalnog temperaturnog profila naspram linearnog.
•Semantic variables fusion of IFSs in conceptual design based on DS evidence theory.•Conflicting beliefs of ambiguity semantics are considering in the concept evaluation.•IFS-VIKOR model based on ...information entropy is proposed to rank the schemes.•A case study of a new tree climbing and trimming machine is applied and constructed.
Quantifying the uncertain linguistic evaluation from decision-makers (DMs) is one of the most challenging parts in the conceptual design decision. Although fuzzy decision models have been widely used to capture potential uncertainty by assigning a fuzzy term with the certain belief, the ambiguity subjective evaluation of semantic variables with conflict beliefs derived from DMs have not been well addressed. To solve this drawback, a concept decision model based on Dempster-Shafer (DS) evidence theory and intuitionistic fuzzy -Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) considering the ambiguity semantic variables fusion is proposed. Firstly, by incorporating semantic variables of intuitionistic fuzzy sets (IFSs), the diversified semantic judgments and its belief will be taken into account to form an ambiguity semantic initial decision matrix; secondly, the DS combination rule will be used to fuse the different semantic variables of multi-DMs in each scheme, update the belief of each semantic variable, and then the semantic fusion value matrix of the scheme will be constructed; finally, the weight of each evaluation objective will be calculated based on the value matrix and information entropy model, IFS-VIKOR model will be constructed to rank the concepts. A case study of the tree climbing and trimming machine will be employed to verify the proposed decision model. This decision model considering diversifying semantic variables and the conflict belief is proven to be effective compared with the IFS-SAW and ISF-TOPSIS.
This study aims at developing a set of appropriate performance evaluation indices mainly based on balanced scorecard (BSC) for extension education centers in universities by utilizing multiple ...criteria decision making (MCDM). Through literature reviews and experts who have real practical experiences in extension education, adequate performance evaluation indices have been selected and then utilizing the decision making trial and evaluation laboratory (DEMATEL) and analytic network process (ANP), respectively, further establishes the causality between the four BSC perspectives as well as the relative weights between evaluation indices. According to this previous result, an empirical analysis of the performance evaluation of extension education centers of three universities at Taoyuan County in Taiwan is illustrated by applying VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). From the analysis results, it indicates that “Learning and growth” is the significant influential factor and it would affect the other three perspectives. In addition, it is discovered that “Internal process” perspective as well as “Financial” perspective play important roles in the performance evaluation of extension education centers. The top three key performance indices are “After-sales service”, “Turnover volume”, and “Net income”. The proposed evaluation model could be considered as a reference for extension education centers in universities to prioritize their improvements on the key performance indices after performing VIKOR analyses.
