A grey-based assessment approach to the site selection of a desalination plant in Libya

PurposeThe purpose of this paper is to propose a supplier selection method using grey system theory for a steelmaking company in Libya.Design/methodology/approachIn order to tackle incompleteness and imprecision of human’s judgments, grey numbers were used. This work uses a grey-based approach to represent decision makers’ comparison judgments and extent analysis method to select the best supplier. Therefore, an example of a selection problem of a steelmaking company in Libya was used to illustrate the proposed approach.FindingsSupplier selection in a supply chain is a critical strategic decision for company’s success and has attracted much attention of both academic scholars and decision makers. The authors have found that the Grey model can play an important role in improving supplier selection strategy, especially when it is in a situation where complex sustainability environments (i.e. Libya) exist.Originality/valueNo literature has been found till date for selection of supplier using grey system theory in a steelmaking company in Libya. An attempt in this regard could enhance a decision-making technique for selecting the best suppliers for the selected case company.

In real life, it is very hard to obtain complete information because of objective conditions and human cognition limitation; hence uncertainty theory becomes an important branch of decision-making problem. The parameters of model are usually of determined values in traditional decision-making theory. Under such environment, Grey systems theory is an important method to do with uncertain decision-making problems. Grey number is used to describe uncertain information. For a set of patterns in the sequence, the thought of Gray target is to find the data which is nearest to target value and construct a standard mode, each mode and standard mode constitutes gray target, the standard mode is the bull's-eye. Grey Target is a method for processing multiple program evaluation and optimization of multiple objective problem. To compare Grey number is very important to obtain scientific and reasonable results for a Grey target decision-making problem. But there is very little study on comparing or ranking Grey numbers. However, in the actual application of Grey number, there are some problems. (1) The probability density function or the whiten function of Grey number is difficult to know. (2) Much information of Grey number will be lost, and at the same time the value of Grey number in uncertainty is lost partly if Grey number is compared and deposed through whiten value which is most commonly used. (3) It is very hard to supply additional information for decision-making in normal condition. Therefore, this paper focuses on handling directly Grey number without whiten value and without distribution function in Grey target decision-making. Furthermore, approach of Grey potential degree could treat the data with both comparing and standardization work. Grey potential could be used as a form of metrics in Grey target decision-making. In order to compare alternatives, consistent standard should be built up. In Grey target decision problem, there are two levels of standard. The alternatives should be selected by values of indexes. So different indexes should be compared and integrated. For each index, which maybe have different source or evaluated by many experts, it needs to combine different information by consistent standard. It is considered that a standard Grey target is set for each index. And then compared to standard Grey target, the Grey potential degree could be used to compare and integrate. Because different index has different measurement scale, each standard Grey target, should be set for each index according to the character of index. However the most important thing is that if every standard Grey target for every index follows the same principle and their Grey potential degrees are calculated by the same approach, it is possible to integrate the judgment of different criteria directly. Hence principle of value-covered set of data of index is adopted. By the ways of Standard Grey Potential Degree, Grey target problem with Grey matrix could be deposed. In order to compare and sort different kinds of Grey numbers, standard Grey potential degree is put forward in the paper. Meanwhile, in multiple Attribute Grey target decision problem, the critical part is target which is complex in different situations. So six aspects of target is discussed and classified, and the series of Objects is sorted by five-step method according to the ascending of value of Standard Grey Total Potential Degree. Three typical examples are also given to verify the efficiency and practicability of our model and algorithm as well. The first one example shows grey target model with multiple index. This situation includes different types of index, income-based type, cost type, central type. The second presents the model of multiple source which have different standard and different weight. The third one is in order to compare with exiting method by the example in a public paper. The third example could not show the character of model fully. Results show that Standard Grey Target should be discussed and Standard Grey potential degree is put forward to connect all kinds of original data to Standard Grey Target. Because the Grey potential degree resolves the relation between two grey numbers, but grey target problem needs more specific application method. Just like the communication center, Standard Grey potential degree is the bridge from method of grey potential degree to grey target decision-making. It is shown from our running result that, the advantages of grey potential based method of grey target decision-making include that the method combines the process of target choosing and Standard deposing, Therefore, the standard grey target model proposed in this research is easy to deal with different kinds attributes of income-type, cost-type and center-type, and the method can be adjusted by superiority and inferior coefficients. The grey target model combined with grey potential degree proposed in this research is able to offer a good model expression, as well as an approach for resolution.

PurposeThe purpose of this paper is to redefine the concept of grey number with information background and to propose novel grey number algorithms.Design/methodology/approachAs the basic element of a grey system, grey number is defined as a number of which the true value is unknown because of the limited information while the boundary or possible value set can be known. Grey number algorithms are key points for constructing grey system models and helping to calculate model results. The concept of grey number is redefined with information background in this paper. Novel grey number algorithms are defined considering all the different forms of grey number information background. Several illustrative examples are applied to state the process of the proposed algorithms.FindingsThe results show that the novel grey number algorithms can do the operations well no matter what the grey number's type. It is useful to create effective grey system models and to do system analysis, forecasting, decision making and control in grey systems.Practical implicationsThe method exposed in the paper can be used to calculate different grey numbers and used in constructing new grey models.Originality/valueThe paper succeeds in defining new grey number algorithm. The concept and its remarks of grey number are discussed. The novel algorithm can be used in creating new grey models and solve the modelling parameters in of grey systems theory undoubtedly.

PurposeThe combination of desalination technology with renewable energy sources (RES) provides a sustainable approach for increasing potable water availability without imposing negative environmental effects. This paper aims to present the development of a platform, which is an internet-based tool integrating the design optimization of desalination systems with spatial modeling based on a geographic information system (GIS).Design/methodology/approachThe proposed platform assists decision-makers to select the optimal location and configuration of both the energy- and water-related subsystems of desalination plants that are power-supplied by RES, such that the lifetime cost of the overall desalination plant is minimized. It enables to optimize the desalination plant site selection and sizing with various hybrid power supply (solar, wind, wave and electrical grid power systems) and desalination technologies combinations, while simultaneously exploiting spatial technologies in an internet-based GIS platform.FindingsA pilot study for the optimal design of stand-alone and grid-connected desalination plants powered by RES is presented, which demonstrates the functionality and features of the proposed platform. It is also shown that a grid-connected desalination plant designed by the proposed software design tool exhibits significantly lower lifetime installation and maintenance costs compared to its stand-alone counterpart.Originality/valueThe proposed platform combines technological, scientific and industrial knowledge with information about societal/political conditions and geo-spatial technologies in a user-friendly graphical interface. Therefore, it provides a design tool enabling its users to secure water supply in a sustainable and economically viable manner.

Purpose – The purpose of this paper is to synthesize the review of the existing literature attached to the grey economic system theory and applications and aims to offer a comprehensive picture of the contribution brought by the researchers to this particular field. Also, the paper underlines the main research areas within the grey economic theory and applications and serves as an informative summary kit for future research works and research directions. Design/methodology/approach – For appreciating the scientific progress made since the grey systems theory has been initiated to the present, with an accent on the literature dedicated to the economic field, a bibliometrics analysis has been conducted. The Perish or Publish software was used for extracting the needed data from Google Scholar for the entire period since the appearance of grey systems to now-a-days. In addition, an ISI Web of Science (WoS) search has been performed for extracting the grey economic papers. As the main focus is on the economic subject area of the grey systems, only the papers related to this field have been selected. Findings – The total number of grey economic paper from both Google Scholar and ISI WoS database, the number of authors, some citation metrics, H-index, authors’ provenience country, papers’ language, etc., have been presented and analysed. Also, a list with the most cited papers in the grey economic relational analysis, grey economic prediction models and grey economic incidence is putted forward. Practical implications – Through the bibliometric analysis on grey economic papers written over time, a qualitative analysis was performed on this field in order to underline the main research direction, to analyse what has been done in this field and to determine which can be the next research directions that can emerge from here. Originality/value – The paper succeeds in enlarging the view regarding the usage of grey systems theory in the economic field, offering a suitable analysis on the considered areas. Even though bibliometrics analysis have been conducted on the grey systems theory field, a grey economic bibliometric analysis has not been done yet, to the authors’ knowledge. Therefore, a synthesized of the existing literature attached to the grey economic system theory and applications is presented in order to offer a more comprehensive picture of the contribution brought by the researchers to this particular field.

Based on the combination of rough set (RS) theory and grey system (GS) theory, this paper presents the grey-rough set modeling using constructive method (CM). Considering grey system theory having good ability in data preprocessing, grey number is used to describe the imprecise, uncertain, vague information in the information system through grey mapping, and then the grey information system is built. In this paper, CM is applied to investigate the RS. the definition of four pairs of approximate operators of grey rough set (GRS) is proposed using CM. At the same time, we investigated the GRS-related fundamental theory and delivered the algebra system of the GRS. It makes that the methods of GS classification can be used to describe the incomplete information more precisely, and enhance the ability of grey information covering, and therefore the connotative knowledge and rule in grey information system can be discovered more effectively and exactly.

Buffer Operator and Theoretical Basis of Grey Systems Theory.- The Design of the Driving-Coupling Algorithm in Unconventional Incidents Based on the Gerts Network.- On the Priority Models of the Grey Interval Preference Relation.- The Nation-State a Systemic View.- Critical Path for a Grey Interval Project Network.- A New Dynamic Clustering Algorithm for an Interval Grey Number.- Research on the New Algorithms of Simple Grey Numbers, Complex Grey Numbers and Multiple Grey Numbers.- Extended Grey Numbers.- Industrial Restructuring of Jiangsu Based on the Grey Linear Programming Model Considering Energy-Saving.- Location of Logistics Distribution Centers with Grey Production Capacity Based on Hybrid PSO.- Grey Incidence Analysis and Application.- The Diagnosis of Firm's Diseases Using the Grey Systems Theory Methods.- Apply GRA in CSL Communication Topics Selection.- The Model of New Grey Incidence and Its Application.- The Analysis of China's Macro-economy with Grey Dynamic Model in 30 Years of Reform and Opening up.- Piecewise Analysis and Prediction of Spring Flow Based ON GM(1,1) Model.- Relational Analysis between Technological Progress and Economic Growth: An Empirical Study in Counties from Jiangsu Province.- Optimization Method of Grey Relation Analysis Based on the Minimum Sensitivity of Attribute Weights.- Research on Extended Cluster of Grey Incidences and Its Application.- Grey Cluster Evaluation Models.- Study of an Improved Grey Integrated Clustering Method and Its Application.- Study of the Influencing Factors of the Development of Chinese Medicine with Gray Clustering Analysis.- Studies of Science and Technology Talent' Management of New Regional Industrial Development: Research with Anhui Province as an Example.- Empirical Research on the Selection of Regional Key Technology for International S&T Cooperation.- Dynamic Evaluation and Analysis of Regional Technological Innovation Capacity Based on a Gray Target.- Analysis of the Regional Characteristics of the Distribution of Scientific and Technological Talents in Jiangsu Province.- The Novel Energy Policy Evaluation Method and Its Application in Oil and Gas Fields in China.- Grey Forecast Model.- The Comparison of Transfer Model and Metabolism GM(1,1) Model in Fuzhou Port's Throughput Prediction.- Research on MGM(1,N|?,r)Model and Application.- A Modified GM(1,1) Model and Its Application.- The Interval Forecasting Method Based on Non-Equidistant GM(1,1) with Application to Regional Grain Production.- An Optimization Method of Estimating Parameters in GM(1,1) Model.- Research on Grey Wave Forecasting Model.- A Method of Modeling Logistics.- An Application of GM(0,N) on Analyzing the First Van Hiele Geometrical Thinking Level.- The Discrete Grey Prediction Model Based on Optimized Initial Value.- The Excel Test Modeling via Four Data in Evaluation of Education Information.- Grey Decision-Making.- The Chain Structure Model of Evolutionary Game of Production-Study-Research Collaboration.- Development and Application of Computer Decision-Making System for Crop Grey Breeding (CDSCGB).- Positive Fractional Linear Systems.- Integrated Method of Grey Multi-attribute Risk Group Decision-Making.- Grey Relational Analysis Method of Linguistic Information and Its Application in Group Decision.- The Relation between Grey Relational Decision Making and Grey Situation Decision Making under the Proper Condition.- Use of Grey System for Assessment of Drinking Water Quality: A Case Study of Jiaozuo City, China.- Grey Cybernetics and Intelligent Services.- Research on the Support System of Dual-Use Core Technologies Integration Based on Open Innovation.- Operational Risk Measurement via the Loss Distribution Approach.- Research on Greedy Simulated Annealing Algorithm for Irregular Flight Schedule Recovery Model.- Network Externality, Call Externality and Price Policy: A Consumer Development Analysis of China's 3G Mobile Data Services.- Coordinating an Online Dual-Channel Supply Chain with Asymmetrical Information.- The Optimization of Supply Chain Components' Quality Characteristics Based on the Structural Equation Model.- The Gap Prediction for the Sci-tech Innovative Talent of Jiangsu Province.- Community Degree, Clustering Coefficient and Knowledge Propagation Efficiency in Complex Networks.- A Study on E-Government Information Sharing.- Research on Situations and Development Trends of Emergency Logistics at Home and Abroad.

Purpose The classification of aircraft failures has been a significant part of functional hazard analysis (FHA). Aiming at the shortcomings of the traditional FHA method in the evaluation of aircraft risk, the purpose of this paper is to put forward a new approach by combining the gray comprehensive relation calculation method in the gray system theory with the traditional FHA in order to deal with the problem of “little data, poor information.” Design/methodology/approach This paper combines FHA, 1–9-scale method and gray relation analysis. At first, aircraft failure scenarios are chosen and data from experts are collected; then gray system theory is applied to find the relevance of such scenarios. Finally, the classification according to relevance is determined. Findings In the past, “little data, poor information” made it difficult for researchers to implement FHA. In this paper, the authors manage to deal with the problem of “poor information” and provide an approach to find the seriousness of aircraft failure. Research limitations/implications Due to the use of expert-evaluating methods, the classification of failures is still a little subjective and can be improved in this area. In the future, the method can be improved from the perspective of combining FMEA to analyze more complex indicators or using multisource heterogeneous solutions to solve fuzzy numbers, probabilities, gray numbers and indicators that cannot be assigned. Practical implications The paper uses FHA to divide the failure state and establishes a gray evaluation model of the aircraft failure state classification to verify the relevant method. Some aircraft safety design requirements are used to check the safety hazards of the aircraft during the design process, and to provide rational recommendations for the functional design of the aircraft. Social implications Improving the safety of aircraft is undoubtedly of great practical significance and has become a top priority in the development of the civil aviation industry. In this paper, the FHA method and the failure state of the aircraft are studied. The original FHA method is innovated by using the gray system theory applicable to the poor information state. Therefore, to some extent, this study has significance for improving the safety of civil aircraft flight, ensuring people’s travel safety and enhancing the society’s trust in civil aviation. Originality/value The main innovation of this paper is integrating the FHA method and the gray system theory. This study calculates the comprehensive relation degree of each failure under different flight stages, and uses FHA to divide the failure state, and finally establishes a gray evaluation model of the aircraft failure state classification to analyze the different conditions of the landing gear brake system, so that it improves the present situation, and the problem with the character of “little data, poor information” can be addressed better.

PurposeThe purpose of this paper is to summarize the advances in grey system theory research and various application achievements in science and engineering. At the same time, it commemorates the 40th anniversary of the birth of grey system theory and the 10th anniversary of Grey Systems–Theory and Application.Design/methodology/approachFirstly, the innovations of theoretical research in grey system theory were summarized and some of the widely recognized new results are briefly described. By searching and combing the research results of grey system theory in China national knowledge infrastructure (CNKI) database and Web of Science by Institute for Scientific Information (ISI), this paper shows the rapid development trend of grey system theory in the past 40 years, and the successful applications of grey system theory in the fields of social sciences, natural sciences and engineering technologies.FindingsMore than 227 thousands literature were found by input 10 phrases such as grey system, grey number and sequence operator etc. in CNKI database. After entering the new century, the number of grey system papers included in CNKI database is increasing rapidly. Since 2008, more than 10 thousands papers have been included per year and more than 15 thousands papers have been included per year since 2014. Grey system method and model are widely used in physics, chemistry, biology and other fields of natural science, as well as transportation, electric power, machinery and other fields of engineering technology, and a large number of valuable results have been achieved.Practical implicationsIt can be seen that the grey system theory plays an important role in promoting China’s scientific and technological progress, innovation and development and high-level talent training from tens of thousands of literatures marked with important national science and technology projects and a large number of grey system literatures published by China’s double first-class universities and double first-class discipline construction universities.Originality/valueBoth innovations of theoretical research and practical application play important role in the growth of new theory. The innovations of theoretical research provide methods and tools for practical application, which is conducive to improve application efficiency and broaden application fields. A large number of practical applications needs have become the source of theoretical innovation and the solid background for the birth of theoretical innovation achievements.

This paper provides a new method for predicting the diameter of electrospun nanofibers. Based on the grey system theory, the effects of polyacrylonitrile mass fraction, voltage, flow rate, and receiving distance on fiber diameter were studied. The GM(1,1) (grey model) model and DNGM(1,1) (The DNGM (1,1) model is based on the whitening differential equation using parameters to Directly estimate the approximate Non-homogeneous sequence Grey prediction Model) model were established to predict fiber diameter by a single-factor change, and the results showed high prediction accuracy. The multi-variable grey model MGM(1,n) (MGM(1,n) is a Multivariate Grey prediction Model) was used for prediction of fiber diameter when multiple factors change simultaneously. The results showed that the average modeling fitting error is 8.62%. The background value coefficients of the MGM(1,n) model were optimized, the average modeling fitting error was reduced to 1.01%, and the average prediction error was reduced to 1.33%. Combining the fractional optimization with the background-value coefficient optimization, the optimal background-value coefficient and the order r were selected. The results showed that the average modeling fitting error is 0.85%, and the average prediction error is 0.38%. The results demonstrate that the grey system theory can effectively predict the diameter of polyacrylonitrile electrospinning fibers with high prediction accuracy. This theory can increase the control of nanofiber diameters in production.

GIS-modelling based coal-fired power plant site identification and selection

PurposeThe widespread application of traditional grey model (GM) in different academic fields such as electrical engineering, education, mechanical engineering and agriculture provided the authors with an incentive to conduct the present empirical research in an accounting field, in particular, auditing practice. In this regard, the purpose of this paper is to employ the nonlinear type of the original GM to forecast the drastically changed data on audit reports, primarily due to the fact that the linear nature of GM is unable to forecast nonlinear data precisely. In essence, this paper adds value to the strand of audit report literature by examining the impact of different financial ratios on auditors’ opinion and then forecasting audit reports by employing GMs.Design/methodology/approachThe grey forecasting model is known as a system containing uncertain information presented by grey numbers, equations and matrices. The grey forecasting model is employed by using a differential equation in an uncertain system with limited data set which is suitable for smoothing discrete data. In addition, the analyses are conducted by applying a sample of top 50 listed companies on the Tehran Stock Exchange during 2011-2016.FindingsThe findings suggest that audit reports are most influenced by the current ratio and conversely, least influenced by the ratio of working capital turnover. Moreover, the authors argue that the Nash nonlinear grey Bernoulli model is more precise than the nonlinear grey Bernoulli model and GM in forecasting audit reports.Originality/valueThe current study may give more strength to stakeholders in order to analyse and forecast audit report.

A research on short term load forecasting problem applying improved grey dynamic model

PurposeThe purpose of this paper is to discuss the animal diet problem in grey environment which is adapted to the real situations. In particular, a new approach to solve these problems is proposed.Design/methodology/approachWith the objective to produce the least-cost diet, in the traditional model for optimizing the diet problem, the price of foods, the nutrients requirements and the necessity of foods requirement have been considered as grey interval numbers. Grey linear programming approach has been employed to solve the grey diet problem. Grey linear programming with flexibility in selection of the coefficients can be more effective for solving the diet problems. In this research, only the positioned method has been used. The grey diet model is solved by using GAMS software based on the positioned method.FindingsThe main contribution of this work is to introduce a new model in the practical case that is concerned with diet problem under a kind of uncertainty environment and furthermore, proposing a novel method to solve the formulated problem. In this way, using a grey model and applying all restrictions, the least cost for one kilogram of total mixed ration was 6,893-10,163 Rials, and at this level, cow’s nutrient requirement was met. Based on the numerical examination, which was done on the real case, the achieved results have showed that the uncertainty of foods requirement and nutrients requirements had slight effect on the animal budget diet.Originality/valueThis problem must be viewed from another perspective because of the uncertainty regarding the amount of nutrients per unit of foods and the diversity of animals’ daily needs to receive them. In particular, a new method to optimize the fully mixed diet of lactating cows in early lactation that are readily available in the northeast of Iran in uncertainty environment has been proposed.

The aims of this study were to forecast change of Chinese social donation in recent years by grey Verhulst model to find out characteristics of social donation and grey correlation analysis which was proposed by Professor Deng Julong is used to detect of an interpersonal relationship between the number of social donations from oversea and the number of foundations. This paper provides a quantitative method to study the trend of Chinese social donation. Grey system theory has been used into economy, administration, society and other fields. The reason is that grey system theory can deal with partially unknown parameters in a system and predict behavior of unknown system within a small data. So grey system theory is superiority to other ways. In order to improve precise, grey system theory is introduced into social donation to explain the phenomenon of social donation. Grey system theory consists of grey Verhulst model and grey relative degree. There is a distinct difference between grey Verhulst model and linear equation because of grey Verhulst model can greatly eliminate the stimulation error in small data. Therefore the reliability of predictive model for social donation is examined by Grey Verhulst model and a relationship of both variables for soical donation and foundation is demonstrated by grey relative degree in the small data. According to the original data of Chinese social donation from China Civil Affairs' Statistical Yearbook as well as China Civil Affairs' website between 2012 and 2016, the original data of social donation has meet basic condition of prediction because the data with S-shaped curve indicates growth saturation by simulation. Based on law of data fitting, model of social donation is built and make calculation by formula of grey Verhulst model. This way needn't take a leap from difference equation to differential equation and this model is tested by mean relative error, predictive value along with relative error by inverse accumulated generating operation. Briefly speaking, the patterns of social donation will be identified by the following steps to achieve high forecast accuracy in small data. Original sequences are (572.50, 566.40, 604.40, 654.50, 827.00). The new sequences are generated by 1-IAGO (Inverse Accumulated Generating Operation) from the original data sequences for (572.5000, −6.1000, 38.0000, 50.1000, 172.5000). Mean generation with consecutive neighbors is (569.4500, 585.4000, 629.4500, 740.7500). Grey differential equation for LSE (Least-Square Estimation) of parameters vector is a=0.7189 and b=0.0013.