Fuzzy AHP and fuzzy TOPSIS integrated hybrid method for auxiliary systems of ship main engines

Although significant technical precautions have been taken in marine diesel engine and auxiliary systems, unexpected failures can be observed during operation. These failures can sometimes lead to irreversible losses. The purpose of the study is to present fuzzy Analytic Hierarchy Process (AHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) methods that can be applied for failure detection in auxiliary systems and marine diesel engine determined by group of experts. By evaluating the decision-making groups, the system most affected by failures was determined. © 2014 Taylor and Francis Ltd. All rights reserved

An interval type-2 fuzzy QUALIFLEX approach to measure performance effectiveness of ballast water treatment (BWT) system on-board ship

Ballast water is of paramount importance for safe and efficient shipping operation since it provides ship’s strength and stability. The ballast water, on the other hand, poses serious marine ecological problems due to the non-indigenous species (NIS) carried in sea water. The International Maritime Organisation introduced International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) to prevent the spread of harmful species from one region to another via ballast water. According to the convention, each ship must be equipped with a proper ballast water treatment system (BWTS). In this context, this paper is aimed at measuring the performance effectiveness of current BWTS used in ships. To achieve this purpose, a Qualitative Flexible (QUALIFLEX) method is used under interval type-2 fuzzy sets (IT2FSs) environment. While the QUALIFLEX handles all possible permutations of the alternatives for outranking, the IT2FSs deal with uncertainty this paper provides practical benefits to ship owners, ship’s safety inspectors, managers and marine environmentalists during decision-making progress of the BWTS settlement on-board ship. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

A fuzzy dematel model proposal for the cause and effect of the fault occurring in the auxiliary systems of the ships' main engine

The ship engine room has a structure that meets a number of needs related to administrative conditions. Even if a simple mechanical error is considered to be the addition of human errors into the complex structure of the engine room, it can lead to undetected loss. How the causes and effects of the detected faults affect the system is as important as an effective fault detection system to detect the fault and take immediate action against any possible engine failure. This study reveals the causes of problems occurring in the main engine auxiliary systems including cooling, lubricating, cooling oil and fuel systems, and the extent of these problems affecting the system. While the Decision Making Trial and Evaluation Laboratory supports to identify and analyze the error detection of auxiliary systems with respect to causal effect relation diagram, fuzzy sets deal with the uncertainty in decision-making and human judgements through the DEMATEL. Therefore, fuzzy DEMATEL approach is applied to examine the causes and the weights of the faults and their relation to each other in the auxiliary systems. When we look at the result of the proposed approach, fuel oil pump failures has more impact on the all system and air cooler problems has the second highest place among the all errors. © 2018 The Royal Institution of Naval Architects

Current strategies and future perspectives of skin-on-a-chip platforms: Innovations, technical challenges and commercial outlook

The skin is the largest and most exposed organ in the human body. Not only it is involved in numerous biological processes essential for life but also it represents a significant endpoint for the application of pharmaceuticals. The area of in vitro skin tissue engineering has been progressing extensively in recent years. Advanced in vitro human skin models strongly impact the discovery of new drugs thanks to the enhanced screening efficiency and reliability. Nowadays, animal models are largely employed at the preclinical stage of new pharmaceutical compounds development for both risk assessment evaluation and pharmacokinetic studies. On the other hand, animal models often insufficiently foresee the human reaction due to the variations in skin immunity and physiology. Skin-on-chips devices offer innovative and state-of-the-art platforms essential to overcome these limitations. In the present review, we focus on the contribution of skin-on-chip platforms in fundamental research and applied medical research. In addition, we also highlighted the technical and practical difficulties that must be overcome to enhance skin-on-chip platforms, e. g. embedding electrical measurements, for improved modeling of human diseases as well as of new drug discovery and development

A novel hybrid MCDM model based on fuzzy AHP and fuzzy TOPSIS for the most affected gas turbine component selection by the failures

Gas turbines are usually the core elements of numerous mechanical systems. Subsequent to the advancement of high efficiency and clean energy, gas turbine has a significantly growing role in different areas, such as aviation and marine propulsion systems, electric power stations, and natural gas and petroleum transportation. However, gas turbines are decisive in operating many industrial plants, and their accompanying maintenance costs are likely to be exceedingly high. A number of failures in the gas turbine components have been detailed and discussed in this paper, with a view to thwarting future breakdowns by suggesting specification for notable maintenance and utilisation of gas turbine components. This study puts forward Fuzzy Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods applied in failure detection of gas turbine components. This paper attempts to handle gas turbine components, which contain hydraulic-pneumatic equipment, electronic control equipment, and bearing equipment. Thanks to the assessment of specialists, heavily influenced by failures, gas turbine components have been decided. The results have proved the bearing equipment to have been the most effective alternative, as being ensued by hydraulic-pneumatic equipment and electronic control equipment