ORCID Profile
0000-0001-6160-6282
Current Organisation
Australian Maritime College
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Publisher: Elsevier BV
Date: 10-2004
Publisher: InTech
Date: 06-03-2013
DOI: 10.5772/53049
Publisher: IGI Global
Date: 2013
DOI: 10.4018/978-1-4666-3942-3.CH013
Abstract: The chapter focuses on the analysis of scaling constants when constructing a utility function over multi-dimensional prizes. Due to fuzzy rationality, those constants are elicited in an interval form. It is assumed that the decision maker has provided additional information describing the uncertainty of the scaling constants’ values within their uncertainty interval. The non-uniform method is presented to find point estimates of the interval scaling constants and to test their unit sum. An analytical solution of the procedure to construct the distribution of the interval scaling constants is provided, along with its numerical realization. A numerical procedure to estimate pvalue of the statistical test is also presented. The method allows making an uncertainty description of constants through different types of probability distributions and fuzzy sets.
Publisher: Unpublished
Date: 2012
Publisher: Unpublished
Date: 2012
Publisher: Informa UK Limited
Date: 04-2008
Publisher: Elsevier BV
Date: 09-2012
Publisher: Elsevier BV
Date: 09-2012
Publisher: Az-buki National Publishing House
Date: 31-08-2021
Abstract: This paper observes different alignment conditions in a journal-bearing-supported machine (i.e. propeller bearings within the stern tube of a marine vessel). A test rig is built so that the driven machine has fixed supports, roller bearings in an electrical motor. An alignment tolerance is met at the coupling of the journal, which is positioned within three journal bearings. This research can be applied to any industry with machines of the same characteristic. The journal bearings are designed to simulate the large tolerance seen in a vessel’s stern tube only for lubrication control oil is used for the bush bearings. Various sensors are placed on the test rig to record data for later machine analysis. Using proximity probes and accelerometers the vibration of the journals and ball bearings can be visualised using orbital plotting and Fast Fourier Transform (FFT) through both LabVIEW and MATLAB respectively. Four alignment procedures are applied to the coupling using a laser unit. The first two will be so that the offset and angular misalignment is produced in the FFT spectrums as per ISO10816 Mechanical vibration so that a reference point is formed for the test rig. The other two alignment procedures represent current industry practice. These procedures are then compared to see which is the preferred reference point that will optimise the reliability value of a whole system. Finding the procedure with minimal vibration will increase the design life of housing structures for such machines, which will increase the overall profit of the shipping industry. Our developments and procedures will be further utilized in practical classes to improve maritime engineering education.
Publisher: IOP Publishing
Date: 03-2020
DOI: 10.1088/1757-899X/797/1/012035
Abstract: We present a case study related to the relocation of parts of port facilities in a Black sea port in Varna (Bulgaria). As the city and the port expanded over the years, the east sector of the port ended up being in the middle of the city center. This causes environmental and spatial planning problems to both the city and the port area. We present several alternatives to relocate part of the industrial activities of the port to another site further to the west sector of the port and utilize the emptied space for recreational, public and social activities. We then apply the Randomized Expert Panel Opinion Marginalizing Procedure (REPOMP) to rank the alternatives. The procedure utilizes a hierarchy of criteria to assess the alternatives from four major aspects – environmental, social, technological and economical. A total of 12 experts provided their estimates on how the alternatives meet all criteria as well as on the relative significance of each criterion. Bootstrap simulation is utilized to not only find the total marginal criterion of each alternative, but also its distribution and best estimate. We also tested whether there is significant difference between the ranking scores of the alternatives.
Publisher: IEEE
Date: 2004
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.THROMRES.2015.02.004
Abstract: Fibrin structure and cellular composition of thrombi profoundly affect the clinical outcomes in ischemic coronary and peripheral artery disease. Our study addressed the interrelations of structural features of thrombi and routinely measured laboratory parameters. Thrombi removed by thromboaspiration following acute myocardial infarction (n=101) or thrombendarterectomy of peripheral arteries (n=50) were processed by scanning electron microscopy and immunostaining for fibrin and platelet antigen GPIIb/IIIa to determine fibrin fibre diameter and relative occupancy by fibrin and cells. Correlations between the structural characteristics and selected clinical parameters (age, sex, vascular localization, blood cell counts, ECG findings, antiplatelet medication, accompanying diseases, smoking) were assessed. We observed significant differences in mean fibre diameter (122 vs. 135 nm), fibrin content (70.5% vs. 83.9%), fluorescent fibrin latelet coverage ratio (0.18 vs. 1.06) between coronary and peripheral thrombi. Coronary thrombi from smokers contained more fibrin than non-smokers (78.1% vs. 62.2% mean occupancy). In the initial 24 h, fibrin content of coronary thrombi decreased with time, whereas in peripheral thrombi platelet content increased in the first 7 days. In coronaries, higher platelet content and smaller vessel diameter were associated with thinner fibrin fibres, whereas hematocrit higher than 0.35 correlated with larger intrathrombotic platelet occupancy. Smoking and dyslipidaemia strengthened the dependence of clot platelet content on systemic platelet count (the adjusted determination coefficient increased from 0.33 to 0.43 and 0.65, respectively). Easily accessible clinical parameters could be identified as significant determinants of ultrastructure and composition of coronary and peripheral thrombi.
Publisher: IEEE
Date: 2004
Publisher: Elsevier
Date: 2018
Publisher: Hindawi Limited
Date: 2010
DOI: 10.1002/INT.20407
Publisher: Elsevier BV
Date: 05-2004
Publisher: Springer Berlin Heidelberg
Date: 2014
Publisher: Fuji Technology Press Ltd.
Date: 20-01-2020
DOI: 10.20965/JACIII.2020.P0026
Abstract: The maturing of autonomous technology has fostered a rapid expansion in the use of Autonomous Underwater Vehicles (AUVs). To prevent the loss of AUVs during deployments, existing risk analysis approaches tend to focus on technicalities, historical data and experts’ opinion for probability quantification. However, data may not always be available and the complex interrelationships between risk factors are often neglected due to uncertainties. To overcome these shortfalls, a hybrid fuzzy system dynamics risk analysis ( FuSDRA ) is proposed. The approach utilises the strengths while overcoming limitations of both system dynamics and fuzzy set theory. Presented as a three-step iterative framework, the approach was applied on a case study to examine the impact of crew operating experience on the risk of AUV loss. Results showed not only that initial experience of the team affects the risk of loss, but any loss of experience in earlier stages of the AUV program have a lesser impact as compared to later stages. A series of risk control policies were recommended based on the results. The case study demonstrated how the FuSDRA approach can be applied to inform human resource and risk management strategies, or broader application within the AUV domain and other complex technological systems.
Publisher: Springer Science and Business Media LLC
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 30-04-2021
Publisher: Springer Science and Business Media LLC
Date: 25-04-2008
Publisher: Atlantis Press
Date: 2013
DOI: 10.2991/.2013.31
Publisher: IEEE
Date: 09-2006
Publisher: Informa UK Limited
Date: 02-01-2019
Publisher: Springer Science and Business Media LLC
Date: 11-2018
Publisher: InTech
Date: 28-02-2011
DOI: 10.5772/14984
Publisher: Informa UK Limited
Date: 30-11-2019
Publisher: Centre of Sociological Research, NGO
Date: 29-11-2018
DOI: 10.14254/JSDTL.2018.3-2.1
Abstract: We present a comprehensive case study to identify the best vessel-specific inventory family that predicts the primary emissions from an ocean-going vessel when at berth, while maneuvering and while cruising. The main purpose of the paper is to generalize the implication of the case study by advising a novel policy, which will allow different authorities to estimate the shipping emissions in a cost-effective and reliable way. The emissions rates of nitrogen oxides, sulphur oxides, carbon dioxide, carbon monoxide, hydrocarbon, and particulate matter from the main engine and from the auxiliary engines are measured for different modes of ship operations in an on-board experiment c aign. The measured total emission amounts were predicted with 13 families of emission inventories and prediction deviations have been calculated. A procedure was advised for estimating the prediction inventory deviations of the combined hourly emission amounts from the main engine plus the auxiliary engines. Each inventory family has been formalized as a six-dimensional vector of prediction deviations for any mode of operation. The best vessel-specific inventory families were identified using the minimal mean absolute deviation criteria. A more rational procedure to rank inventories is considered, which treats the missing value problem and constructs a six-attribute value function. The use of preferential analysis and value functions further clarifies the recommended choice of inventory method. In this case study we demonstrated that the most suitable inventory families will provide reliable predictions with acceptable deviations from the measured emissions. At berth and for maneuvering, the best inventory family turned out to be MOPSEA (with 32.2% and 39.6% mean absolute deviations respectively). For cruising, the most precise inventory family is MEET (with 59.2% mean absolute deviation), whereas MOPSEA being the third best. However, some of the other inventories produce unacceptably high deviation, well above 100%. The practical implication is that while inventory methods can produce precise and cost-effective predictions, they should never be used without experimental verification. That is why, we provide an algorithm to use on-board experimental measurements to identify the best vessel-specific inventory family, which predicts the primary emission of a ship at a given mode of operation. The proposed algorithm and the implications of the case study are utilized to motivate a proposal for a novel future policy for a cost-effective and reliable emission estimation from shipping.
Publisher: Elsevier BV
Date: 03-2019
Publisher: Walter de Gruyter GmbH
Date: 30-09-2008
DOI: 10.2478/S11535-008-0035-4
Abstract: Progress curve analysis is a convenient tool for the characterization of enzyme action: a single reaction mixture provides multiple experimental measured points for continuously varying amounts of substrates and products with exactly the same enzyme and modulator concentrations. The determination of kinetic parameters from the progress curves, however, requires complex mathematical evaluation of the time-course data. Some freely available programs (e.g. FITSIM, DYNAFIT) are widely applied to fit kinetic parameters to user-defined enzymatic mechanisms, but users often overlook the stringent requirements of the analytic procedures for appropriate design of the input experiments. Flaws in the experimental setup result in unreliable parameters with consequent misinterpretation of the biological phenomenon under study. The present commentary suggests some helpful mathematical tools to improve the analytic procedure in order to diagnose major errors in concept and design of kinetic experiments.
Publisher: Prof. Marin Drinov Publishing House of Bulgarian Academy of Sciences
Date: 30-11-2018
Publisher: Springer Berlin Heidelberg
Date: 2008
Publisher: Informa UK Limited
Date: 07-2010
Publisher: MDPI AG
Date: 11-10-2021
DOI: 10.3390/MATH9202547
Abstract: We analyze the influence of repair on a two-component warm-standby system with switching and back-switching failures. The repair of the primary component follows a minimal process, i.e., it experiences full aging during the repair. The backup component operates only while the primary component is being repaired, but it can also fail in standby, in which case there will be no repair for the backup component (as there is no indication of the failure). Four types of system failures are investigated: both components fail to operate in a different order or one of two types of switching failures occur. The reliability behavior of the system is investigated under three different aging assumptions for the backup component during warm-standby: full aging, no aging, and partial aging. Four failure and repair distributions determine the reliability behavior of the system. We analyzed two cases—in the First Case, we utilized constant failure rate distributions. In the Second Case, we applied the more realistic time-dependent failure rates. We used three methods to identify the reliability characteristics of the system: analytical, numerical, and simulational. The analytical approach is limited and only viable for constant failure rate distributions i.e., the First Case. The numerical method integrates simultaneous Algebraic Differential Equations. It produces a solution in the First Case under any type of aging, and in the Second Case but only under the assumption of full aging in warm-standby. On the other hand, the developed simulation algorithms produce solutions for any set of distributions (i.e., the First Case and the Second Case) under any of the three aging assumptions for the backup component in standby. The simulation solution is quantitively verified by comparison with the other two methods, and qualitatively verified by comparing the solutions under the three aging assumptions. It is numerically proven that the full aging and no aging solutions could serve as bounds of the partial aging case even when the precise mechanism of partial aging is unknown.
Publisher: Springer Science and Business Media LLC
Date: 22-08-2021
Publisher: IEEE
Date: 08-2020
Publisher: IEEE
Date: 09-2008
Publisher: IEEE
Date: 07-2010
Publisher: IEEE
Date: 07-2010
Publisher: Elsevier BV
Date: 2015
Publisher: S. Karger AG
Date: 2016
DOI: 10.1159/000444511
Publisher: Science Publications
Date: 04-2018
Publisher: Springer Science and Business Media LLC
Date: 2015
Publisher: Fuji Technology Press Ltd.
Date: 20-01-2005
DOI: 10.20965/JACIII.2005.P0061
Abstract: The paper aims at making a contribution to the axiomatic approach to subjective uncertainty by introducing a modified set of six axioms to subjective probabilities. Those are considered sufficient to guarantee adequacy and rationality in the expression of beliefs in future uncertain events by the observer of the system. The axioms combine mathematical correctness and unambiguous justification. They draw on existing axiomatic bases, but include some additional features and dependencies. A modified theorem for existence and uniqueness of subjective probabilities that uses the axioms discussed is also stated in the paper, and some explanation is given regarding the way to acquire its strict mathematical justification.
Publisher: IGI Global
Date: 2015
DOI: 10.4018/978-1-4666-8333-4.CH002
Abstract: This chapter discusses several applications of the REPOMP procedure (Randomized Expert Panel Opinion Marginalizing Procedure). It analyzes the subjective opinion of an expert panel in a multi-criteria decision making situation. It starts with an expert panel constructing a hierarchical structure of criteria to evaluate the alternatives. At a next stage, the same expert panel evaluates the relative weight of each criterion and the degree of compliance of each alternative with those criteria. Then a randomized procedure is applied to calculate the marginal indicator of each alternative and make the final ordering based on it. Additional simulation procedure is applied to analyze the distribution of that marginal indicator. The alternatives are also being allocated to indifference classes using hypothesis testing procedures. The analyzed ex les refer to issues in environmental management, energy efficiency and spatial data infrastructures.
Publisher: Az-buki National Publishing House
Date: 31-08-2021
Abstract: We present a system for technical diagnostics (TD) that can recognize the actual state of marine equipment. A Bayesian classifier is trained to identify the different classes of a piece of equipment, monitored through multiple pseudo-discrete features. Data learning s les can be acquired with direct experiments for each class. The system is capable of merging subjective expert knowledge and data learning s les using pseudo-Bayesian estimates when the parameters of the conditional likelihood for the classes are identified. In the training process, correction is applied to solve numerical problems arising from zero probabilities. The pseudo-discrete features have hybrid nature and combine probabilistic and fuzzy approaches. They combine the ease of extracting subjective expert knowledge typical for the discrete features with the high precision of using the measured data during recognition typical for the continuous features. The domain of each pseudo discrete feature is ided into several main categories of non-overlapping intervals which are described as words by the expert. If a measured feature falls between two consecutive categories it is treated as a linear combination of those categories. The resubstitution performance of the classifier is assessed using an error matrix. A numerical ex le of a marine diesel generator demonstrates the proposed algorithm in a classification problem with nine different state classes of the generator, monitored through 23 pseudo-discrete features. Data learning s les are acquired with direct experiments for each class. The created TD system has potential applications in other complex engineering systems and may support improvements in marine engineering education and training.
Publisher: Fuji Technology Press Ltd.
Date: 20-05-2006
DOI: 10.20965/JACIII.2006.P0419
Abstract: A Bayesian pattern recognition system is proposed, that processes information encoded by four types of features: discrete, pseudo-discrete, multi-normal continuous and independent continuous. This hybrid system utilizes the combined frequentist-subjective approach to probabilities, uses parametric and nonparametric techniques for the conditional likelihood estimation, and relies heavily on the fuzzy theory for data presentation, learning, and information fusion. The information for training, recognition, and prediction of the system is organized in a database, which is logically structured into three interconnected hierarchical sub-databases. A software tool is created under MATLAB that assures consistency, integrity, and maintenance of the database information. Three application ex les from the fields of technical and medical diagnostics are presented, which illustrate the types of problems and levels of complexity that the database tool can handle.
Publisher: Medical University Prof. Dr. Paraskev Stoyanov - Varna
Date: 31-12-2018
Publisher: Springer Berlin Heidelberg
Date: 02-11-2014
Publisher: Elsevier BV
Date: 04-2022
Publisher: IEEE
Date: 09-2006
Publisher: Fuji Technology Press Ltd.
Date: 20-01-2005
DOI: 10.20965/JACIII.2005.P0065
Abstract: The paper presents a discussion on fuzzy rationality in the elicitation of subjective probabilities and utilities. In addition to previous research, two functions, measuring the degree of preference of the real decision maker on both sides of the uncertainty interval are introduced, and their relationship with the indifference function, measuring the degree of indifference of the decision maker over gambles, is analyzed and graphically interpreted. A new relation -- hesitation -- is introduced to give a better description of the actual process of subjective elicitation by real decision makers. The influence of the preference-hesitation combination in an elicitation process is presented graphically, and it is argued that the resulting uncertainty interval is much tighter than the one, resulting from the preference-indifference based elicitation.
Publisher: IEEE
Date: 08-2020
Start Date: 2016
End Date: 2017
Funder: International Association of Maritime Universities
View Funded ActivityStart Date: 2019
End Date: 2019
Funder: University of Tasmania
View Funded Activity