scholarly journals MAINTENANCE CONTRACT MODEL FOR COMPLEX ASSET/EQUIPMENT

2014 ◽  
Vol 21 (01) ◽  
pp. 1450002 ◽  
Author(s):  
ANISUR RAHMAN
Keyword(s):  
Mathematical Models ◽  
Conceptual Model ◽  
Preventive Maintenance ◽  
Cost Models ◽  
Numerical Examples ◽  
Contract Price ◽  
The Past ◽  
Penalty Costs ◽  
Original Equipment Manufacturers

Maintenance contracts received significant attentions in the past 15 to 20 years as it has huge potential to reduce the upfront investments in maintenance infrastructure, specialized maintenance facilities, and risks to the owners through expert services provided by the original equipment manufacturers and/or specialist maintenance providers. To make maintenance contracts more effective, there is a need to develop mathematical models and understand future costs that could be built into the contract price. In this paper, a conceptual model is developed for estimating cost of outsourcing maintenance of complex and critical asset/equipment taking into account both corrective and preventive maintenance as servicing strategies and risks and penalty costs associated with such contract. The developed cost models are analyzed using illustrated numerical examples.

Cost management for concrete batch plant using stochastic mathematical models

2006 ◽  
Vol 33 (8) ◽  
pp. 1065-1074 ◽  
Author(s):  
Tarek M Zayed ◽  
Ibrahim A Nosair
Keyword(s):  
Mathematical Models ◽  
Production Efficiency ◽  
Cost Management ◽  
Unit Cost ◽  
Expected Value ◽  
Cost Models ◽  
Productivity Cost ◽  
Batch Plant ◽  
Factor Share ◽  
Construction Operation

Assessing productivity, cost, and delays are essential to manage any construction operation, particularly the concrete batch plant (CBP) operation. This paper focuses on assessing the above-mentioned items for the CBP using stochastic mathematical models. It aims at (i) identifying the potential sources of delay in the CBP operation; (ii) assessing their influence on production, efficiency, time, and cost; and (iii) determining each factor share in inflating the CBP concrete unit expense. Stochastic mathematical models were designed to accomplish the aforementioned objectives. Data were collected from five CBP sites in Indiana, USA, to implement and verify the designed models. Results show that delays due to management conditions have the highest probability of occurrence (0.43), expected value of delay percent (62.54% out of total delays), and relative delay percent. The expected value of efficiency for all plants is 86.53%; however, the average total expense is US$15.56/m3 (all currency are in US$). In addition, the expected value of effective expenses (EE) is $18.03/m3, resulting in extra expenses (XE) of $2.47/m3. This research is relevant to both industry practitioners and researchers. It develops models to determine the effect of delays on concrete unit cost. They are also beneficial to the CBP management.Key words: concrete batch plant, delays, management conditions, cost models, cost management, stochastic mathematical models.

Modelling and computation of liquid crystals

Acta Numerica ◽  
2021 ◽  
Vol 30 ◽  
pp. 765-851
Author(s):  
Wei Wang ◽  
Lei Zhang ◽  
Pingwen Zhang
Keyword(s):  
Liquid Crystals ◽  
Numerical Methods ◽  
Mathematical Models ◽  
Soft Matter ◽  
Scientific Research ◽  
Crystalline Solids ◽  
The Past ◽  
Tremendous Progress

Liquid crystals are a type of soft matter that is intermediate between crystalline solids and isotropic fluids. The study of liquid crystals has made tremendous progress over the past four decades, which is of great importance for fundamental scientific research and has widespread applications in industry. In this paper we review the mathematical models and their connections to liquid crystals, and survey the developments of numerical methods for finding rich configurations of liquid crystals.

scholarly journals On numerical solver selection and related uncertainty terminology

2009 ◽  
Vol 12 (3) ◽  
pp. 241-250 ◽  
Author(s):  
Petra Claeys ◽  
Ann van Griensven ◽  
Lorenzo Benedetti ◽  
Bernard De Baets ◽  
Peter A. Vanrolleghem
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Models ◽  
Process Design ◽  
Uncertainty Assessment ◽  
Environmental Modelling ◽  
Chemical Systems ◽  
The Past ◽  
Numerical Solver ◽  
Physical And Chemical ◽  
Insight Into

Mathematical models provide insight into numerous biological, physical and chemical systems. They can be used in process design, optimisation, control and decision support, as acknowledged in many different fields of scientific research. Mathematical models do not always yield reliable results and uncertainty should be taken into account. At present, it is possible to identify some factors contributing to uncertainty, and the awareness of the necessity of uncertainty assessment is rising. In the fields of Environmental Modelling and Computational Fluid Dynamics, for instance, terminology related to uncertainty exists and is generally accepted. However, the uncertainty due to the choice of the numerical solver and its settings used to compute the solution of the models did not receive much attention in the past. A motivating example on the existence and effect of numerical uncertainty is provided and clearly shows that we can no longer ignore it. This paper introduces a new terminology to support communication about uncertainty caused by numerical solvers, so that scientists become perceptive to it.

scholarly journals Presentation a Conceptual Model to Explain Determinants of Breakthrough the Islamic Banking Marketing: A Managerial Perspective

2014 ◽  
Vol 39 ◽  
pp. 58-66
Author(s):  
Seyed Reza Seyed-Javadin ◽  
Reza Raei ◽  
Mohammad Javad Iravani ◽  
Mohammad Safari
Keyword(s):  
Conceptual Model ◽  
Financial Services ◽  
Islamic Banking ◽  
Marketing Capabilities ◽  
Great Opportunity ◽  
The Past ◽  
Proposed Model ◽  
Determining Factors ◽  
Descriptive Method ◽  
Managerial Perspective

Taking advantage of applications of marketing in the Islamic banking is a great opportunity for this area to gain competitive advantage in the today’s turbulent business and market. Specialized field of Islamic banking marketing is a subset of marketing management has received less attention and consideration. Islamic banking (IB) is one of the growing fields in the today's economy. To achieve more advancement in the IB it is necessary that recent findings of the other research and practical areas to be used and implemented. Scholars and experts believe that the market for Islamic banking has grown rapidly over the past few years, and this robust growth is expected to continue for the foreseeable future. In many markets, Islamic banking has evolved from being a niche offering into being part of the mainstream financial services landscape. Marketing capabilities can provide the convenient and required ground for the continued growth of Islamic banking. This study aimed at present a conceptual model to explain the determining factors to achieve the IB marketing from managerial perspective. Using a descriptive method this study tried to identify and present the main factors from managerial perspective that affected on the IB marketing. Proposed model and appropriated explanations have been provided in the paper.

Synchrotron radiation from single electrons gyrating in a magnetoactive plasma

1969 ◽  
Vol 47 (7) ◽  
pp. 757-768 ◽  
Author(s):  
P. C. W. Fung
Keyword(s):  
Synchrotron Radiation ◽  
Plasma Frequency ◽  
Radiation Power ◽  
Magnetoactive Plasma ◽  
Electron Plasma ◽  
Relativistic Electrons ◽  
Relative Importance ◽  
Numerical Examples ◽  
The Past ◽  
Single Electrons

In this paper, the incoherent synchrotron radiation power emitted by relativistic electrons gyrating in a cold magnetoactive plasma is rederived, correcting errors which have occurred in the past literature. One can specify the background plasma by the quantity A = ωp2/ωH2 (ωp is the angular electron plasma frequency and ωH is the angular electron gyro-frequency), i.e. the relative importance of the plasma frequency to the gyro-frequency. The general spectral features of synchrotron radiation from single electrons radiating in plasmas of large [Formula: see text] and small [Formula: see text] are discussed with the aid of a number of numerical examples.

Design and Analysis of Computer Experiments

2017 ◽  
pp. 264-279
Author(s):  
Xinwei Deng ◽  
Ying Hung ◽  
C. Devon Lin
Keyword(s):  
Complex Systems ◽  
Mathematical Models ◽  
Gaussian Process ◽  
Computer Simulations ◽  
Process Modeling ◽  
Computer Experiments ◽  
Space Filling ◽  
Science And Engineering ◽  
The Past ◽  
Statistical Approaches

Computer experiments refer to the study of complex systems using mathematical models and computer simulations. The use of computer experiments becomes popular for studying complex systems in science and engineering. The design and analysis of computer experiments have received broad attention in the past decades. In this chapter, we present several widely used statistical approaches for design and analysis of computer experiments, including space-filling designs and Gaussian process modeling. A special emphasis is given to recently developed design and modeling techniques for computer experiments with quantitative and qualitative factors.

Just-In-Time Exchange Relationships in Industrial Markets

1988 ◽  
Vol 52 (4) ◽  
pp. 52-67 ◽  
Author(s):  
Gary L. Frazier ◽  
Robert E. Spekman ◽  
Charles R. O'Neal
Keyword(s):  
Just In Time ◽  
Relational Exchange ◽  
Key Factors ◽  
Exchange Relationship ◽  
Exchange Relationships ◽  
The Core ◽  
The Past ◽  
Industrial Markets ◽  
New Form ◽  
Original Equipment Manufacturers

A new form of relational exchange, commonly referred to as the “just-in-time” (JIT) exchange relationship, has been adopted and implemented by many original equipment manufacturers (OEMs) and suppliers of component parts-materials during the past several years. Though the “exchange relationship” is at the core of the marketing discipline, JIT exchanges have received little attention in the marketing literature. The authors attempt to expand understanding of (1) how JIT exchanges compare with other forms of exchange between suppliers of component parts-materials and OEMs, (2) what conditions are most conducive to the initiation of JIT exchanges, and (3) what key factors are likely to influence the success or failure of initiated JIT exchanges.

scholarly journals Assessing the Effect of Mycotoxin Combinations: Which Mathematical Model Is (the Most) Appropriate?

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 153 ◽  
Author(s):  
Domagoj Kifer ◽  
Daniela Jakšić ◽  
Maja Šegvić Klarić
Keyword(s):  
Mathematical Models ◽  
Combination Index ◽  
Dose Effect ◽  
Additive Effects ◽  
Biological Models ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Surface Code ◽  
Definition Of ◽  
Bliss Independence

In the past decades, many studies have examined the nature of the interaction between mycotoxins in biological models classifying interaction effects as antagonisms, additive effects, or synergisms based on a comparison of the observed effect with the expected effect of combination. Among several described mathematical models, the arithmetic definition of additivity and factorial analysis of variance were the most commonly used in mycotoxicology. These models are incorrectly based on the assumption that mycotoxin dose-effect curves are linear. More appropriate mathematical models for assessing mycotoxin interactions include Bliss independence, Loewe’s additivity law, combination index, and isobologram analysis, Chou-Talalays median-effect approach, response surface, code for the identification of synergism numerically efficient (CISNE) and MixLow method. However, it seems that neither model is ideal. This review discusses the advantages and disadvantages of these mathematical models.

Mathematical Solution for the Determination of Optimal Warehouse Location and Optimal Distribution Route

2005 ◽  
Author(s):  
Jagannadha Rao Naraparaju ◽  
Raghunandan A. Karamcheti ◽  
Z. Y. Wang
Keyword(s):  
Mathematical Models ◽  
Optimal Location ◽  
Optimal Routing ◽  
Practical Case ◽  
Transport Costs ◽  
Numerical Examples ◽  
Warehouse Location ◽  
Transportation Distance

In this paper, a procedure to determine the optimal location of a distribution warehouse, from which products are sent out to a group of companies has been studied. The goal was to minimize annual transportation distance between the warehouse and the customers. Fundamentals of mathematics have been used to formulate a virtual map showing the location of the present customers. Mathematical models and equations were developed making certain assumptions and an optimal location for the warehouse has been determined. Various factors that are involved in relocating the warehouse have been considered. Also a solution is given for the optimal location of a satellite or an auxiliary warehouse in addition to the existing one. A case study has been conducted on the model with the help of various numerical examples. Based on the optimal location of the relocated warehouse and the satellite warehouse obtained, the reductions in the transport costs were estimated. Once the optimal warehouse location has been found out, the next step was to find out an optimal route (least travel distance) for a practical case in which several companies have to be supplied with necessary products from one warehouse in a single trip. For this purpose, mathematical models were created and optimal routing algorithms were developed. Case studies have been conducted with the help of numerical examples. High amounts of savings in terms of travel distances, costs and time could be observed by the implementation of these algorithms.

scholarly journals Portfolio Selection Based on Distance between Fuzzy Variables

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Weiyi Qian ◽  
Mingqiang Yin
Keyword(s):  
Mathematical Models ◽  
Portfolio Selection ◽  
Expected Value ◽  
Simple Method ◽  
Numerical Examples ◽  
Fuzzy Variables ◽  
Fuzzy Environment ◽  
Investment Return ◽  
New Models ◽  
Different Types

This paper researches portfolio selection problem in fuzzy environment. We introduce a new simple method in which the distance between fuzzy variables is used to measure the divergence of fuzzy investment return from a prior one. Firstly, two new mathematical models are proposed by expressing divergence as distance, investment return as expected value, and risk as variance and semivariance, respectively. Secondly, the crisp forms of the new models are also provided for different types of fuzzy variables. Finally, several numerical examples are given to illustrate the effectiveness of the proposed approach.

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