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Multi-objective optimization algorithms with the island metaheuristic for effective project management problem solving
Christina Brester, Ivan Ryzhikov, Eugene Semenkin, 2017, original scientific article

Abstract: Background and Purpose: In every organization, project management raises many different decision-making problems, a large proportion of which can be efficiently solved using specific decision-making support systems. Yet such kinds of problems are always a challenge since there is no time-efficient or computationally efficient algorithm to solve them as a result of their complexity. In this study, we consider the problem of optimal financial investment. In our solution, we take into account the following organizational resource and project characteristics: profits, costs and risks. Design/Methodology/Approach: The decision-making problem is reduced to a multi-criteria 0-1 knapsack problem. This implies that we need to find a non-dominated set of alternative solutions, which are a trade-off between maximizing incomes and minimizing risks. At the same time, alternatives must satisfy constraints. This leads to a constrained two-criterion optimization problem in the Boolean space. To cope with the peculiarities and high complexity of the problem, evolution-based algorithms with an island meta-heuristic are applied as an alternative to conventional techniques. Results: The problem in hand was reduced to a two-criterion unconstrained extreme problem and solved with different evolution-based multi-objective optimization heuristics. Next, we applied a proposed meta-heuristic combining the particular algorithms and causing their interaction in a cooperative and collaborative way. The obtained results showed that the island heuristic outperformed the original ones based on the values of a specific metric, thus showing the representativeness of Pareto front approximations. Having more representative approximations, decision-makers have more alternative project portfolios corresponding to different risk and profit estimations. Since these criteria are conflicting, when choosing an alternative with an estimated high profit, decision-makers follow a strategy with an estimated high risk and vice versa. Conclusion: In the present paper, the project portfolio decision-making problem was reduced to a 0-1 knapsack constrained multi-objective optimization problem. The algorithm investigation confirms that the use of the island meta-heuristic significantly improves the performance of genetic algorithms, thereby providing an efficient tool for Financial Responsibility Centres Management.
Keywords: 0-1 multi-objective constrained knapsack problem, project management portfolio problem, multi-objective evolution-based optimization algorithms, collaborative and cooperative meta-heuristics
Published: 04.05.2018; Views: 716; Downloads: 213
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Tourist farm service quality assessment
Karmen Pažek, Črtomir Rozman, 2010, review article

Abstract: Farm tourism shows a structure different from agriculture, forestry, and fishery; farm tourism is expanding, labour intensive, generates an influx of money, and maintains the service base in the region. Farm tourism is one of the most important supplementary activities and generates considerable secondary income. This paper present the developed methodology that will enable the ranking of tourist farms based on their service quality. This is accomplished through the use of the expert system based on the DEXi decision-making method. Using DEXi, the multi-criteria decision model for the assessment of farm tourism-s service quality was developed. The model was applied in practice on 7 vacation farms. The data from the questionnaires completed by farm guests and hosts was used as input data in the multi-attribute model and as an arbitrary estimation for the farm. The results of the model are shown as the assessments for individual farms. Out of seven chosen farms, four achieved the best possible estimation. Two of them achieved middle estimation. For the last tourist farm, where a data deficit was present, the model showed two final possible estimations (very good or good and bad - depends on value of missing attributes.
Keywords: tourist farm, multi-criteria analysis, DEXi methodology, ranking
Published: 29.03.2018; Views: 363; Downloads: 77
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Simulated decision learning in a multiactor setting
Viveca Asproth, Stig Holmberg, Ulrica Löfstedt, 2010, original scientific article

Abstract: The idea of decision analysis-and subsequent learning from the outcomes-is old within Operational Research. Here this approach to continuous improvement of decision outcomes is put one step further within the area of crisis and disaster management. This is done by introducing multiactors making simultaneous decisions with just partial information about each other. Further, decision outcomes are achieved from a simulation model rather than from the real object system.
Keywords: multi layered systems, anticipation, retardation, learning, simulation
Published: 22.01.2018; Views: 585; Downloads: 235
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The impact of transport infrastructure projects on sustainable development within a major logistics gateway in North West England
Dimitrios Paraskevadakis, Alan Bury, Jin Wang, Jun Ren, Stephen Bonsall, Ian Jenkinson, 2016, original scientific article

Abstract: In the North West of England the issue of a perceived infrastructure gap is of increasing concern. Investment needs to be made to improve the transport infrastructure of the region if it is to be expected to promote the development of its own regional logistics gateway. Funding tools have been set up to address the challenges arising from the imbalance in infrastructure development that exists between regions in the north of the United Kingdom and those in the south. For regions with well developed economies the outlook is promising as the availability of modern transport infrastructure looks set to improve. However, some sources believe that the development of new transport infrastructure will have a negative impact upon sustainable development. It is expected that this will occur in a range of both direct and indirect ways. As a result, it is critical that planning for the creation of new intermodal transport infrastructure, or the upgrading of that which already exists, takes into account the impact that these developments will have on the sustainable development of the host region. A scenario based development methodology is proposed in this paper. It was developed to provide a way to identify potential scenarios that may arise within a given region as a result of transport infrastructure projects. To create significant scenarios the methodology is dependent on the availability of a sufficient quantity of quality data. For this paper that data was collected through a focus group composed of stakeholders from the region in question. This was further supported by the performance of an impact survey using the same group of stakeholders.
Keywords: multi-modal logistics, gateways north west england, focus group, impact survey, scenarios
Published: 17.11.2017; Views: 943; Downloads: 243
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System dynamic models as decision-making tools in agritourism
Tadeja Jere Lazanski, 2016, original scientific article

Abstract: Agritourism as a type of niche tourism is a complex and softly defined phaenomenon. The demands for fast and integrated decision regarding agritourism and its interconnections with environment, economy (investments, traffic) and social factors (tourists) is urgent. Many different methodologies and methods master softly structured questions and dilemmas with global and local properties. Here we present methods of systems thinking and system dynamics, which were first brought into force in the educational and training area in the form of different computer simulations and later as tools for decision-making and organisational re-engineering. We develop system dynamics models in order to present accuracy of methodology. These models are essentially simple and can serve only as describers of the activity of basic mutual influences among variables. We will pay the attention to the methodology for parameter model values determination and the so-called mental model. This one is the basis of causal connections among model variables. At the end, we restore a connection between qualitative and quantitative models in frame of system dynamics.
Keywords: agritourism, multi-criteria decision-making, modelling, system dynamics
Published: 14.11.2017; Views: 573; Downloads: 101
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Designing a strategic mobility plan for small and medium sized cities using a multi-stage methodology
Uroš Kramar, Tina Cvahte, Marjan Sternad, Darja Topolšek, 2015, original scientific article

Abstract: Urban mobility is one of the crucial factors of quality of life in cities. Therefore, an effective mobility system and its holistic planning are of utmost importance for sustainable and quality development of urban centres. This paper focuses on holistic and integrated strategic planning of a mobility system. The used multi % step methodology was tested on a case of a city of Celje, Slovenia. With the first round of focus groups, information about the specific urban mobility system was gathered which was used to develop a SWOT matrix. This was the foundation for the execution of a second round of focus groups, where the output was a proposition for a strategic plan for mobility development in small and medium sized cities.
Keywords: urban mobility, strategy, planning, multi-stage methodology
Published: 03.08.2017; Views: 687; Downloads: 90
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Considering interactions among multiple criteria for the server selection
Vesna Čančer, 2010, original scientific article

Abstract: Decision-making about server selection is one of the multi-criteria decision-making (MCDM) processes where interactions among criteria should be considered. The paper introduces and develops some solutions for considering interactions among criteria in the MCDM problems. In the frame procedure for MCDM by using the group of methods, based on assigning weights, special attention is given to the synthesis of the local alternatives' values into the aggregate values where the mutual preferential independence between two criteria is not assumed. Firstly, we delineate how to complete the additive model into the multiplicative one with synergic and redundancy elements in the case that criteria are structured in one level and in two levels. Furthermore, we adapted the concept of the fuzzy Choquet integral to the multi-attribute value theory. Studying and comparing the results of the example case of the server selection obtained by both aggregation approaches, the paper highlights the advantages of the first one since it does not require from decision makers to determine the weights of all possible combinations of the criteria and it enables the further use of the most preferred MCDM methods.
Keywords: interaction, multi-criteria decision-making, preferential dependence, server
Published: 03.08.2017; Views: 544; Downloads: 72
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Heritage trails through Dolenjska and Bela Krajina in Slovenia
Marko Koščak, 2016, review article

Abstract: One of the crucial methodologies for growing and developing a level of tourism which is sustainable and enhances the totality of local and regional environments is a multi-stakeholder approach to tourism development. In this paper, we present the case of the 'Heritage trails through Dolenjska and Bela krajina in SE Slovenia' in which sustainable rural development (we take this to include cultural & heritage, vinicultural & gastronomic, as well as ecological tourism) is one of the key elements of the integral mix of business economy, viz. development of the region in the SE of Slovenia. The integral approach showed from the very beginning of project activities, within the Novo Mesto chamber of commerce, its long-time implementation until the present, as one of the key products within the tourist destination of Dolenjska, Bela Krajina and Kočevsko-Ribniška. It takes an integrated approach in terms of start-up, implementation and development and is supported by and benefits from the notion of a core of multiple stakeholders.
Keywords: Slovenia, multi-stakeholder approach, partnership, Integrated project Heritage Trail Dolenjska & Bela krajina, sustainable tourism
Published: 03.08.2017; Views: 619; Downloads: 79
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Multi-objective synthesis of company’s supply-networks based on integration of renewable resources
Annamaria Vujanović, 2017, doctoral dissertation

Abstract: The aim of this doctoral dissertation was to develop a general methodology for sustainable integration of company's supply networks into nearby regional networks by i) integrating renewables, thereby increasing company's energy self-sufficiency, ii) by performing multi-objective synthesis in order to obtain economically efficient and yet environmentally benign or even unburdening solutions, and iii) to perform dynamic and stochastic synthesis under uncertainties in dynamically changing market conditions in order to obtain more reliable and realistic solutions. The research work is directly interlinked with a large-scale European meat producing company Perutnina Ptuj d.d., which is located in the heart of Slovenia. The aim of the first part was to integrate renewables into companies’ supply-networks at regional level in order to maximize the self-sufficiencies of their energy supplies. This concerns companies’ activities from the use of natural resources to supplying their final products to the customers being interlinked with their regional networks. A Mixed-Integer Linear Programming (MILP) model has been developed for the integration of both the companies’ and surrounding regional supply-networks and the utilization of different types of renewables as sources for the companies’ energy supplies. The potential renewable energy sources, which are located within companies surrounding region are solar, biomass, organic and animal wastes. The result indicates that by sufficient integration of renewables into companies’ supply networks, profitable and yet energy self-sufficient solutions can be obtained. The second part presents the multi-objective synthesis of a company’s supply-network by integrating renewables and accounting for several environmental footprints. A previously developed model for achieving energy self-sufficiency by integrating renewables into companies’ supply-networks has been extended for the evaluation of environmental impacts, such as energy, carbon, nitrogen, and water footprints. The achievement of an energy self-sufficient supply-network has been considered whilst significantly reducing environmental impacts. Direct (burdening) and indirect (unburdening) effects that form total effects on the environment are considered for the evaluation of environmental footprints. This approach identifies those alternative energy production technologies that are more profitable and environmentally more benign with significant unburdening capabilities. The results showed significant unburdening of the environment in terms of carbon and nitrogen footprints; however, higher burdening in terms of the water footprint. The third part presents a multi-objective MILP synthesis of a dynamic supply-network under uncertainty applied to the company. The previously-developed multi-objective model for achieving energy self-sufficiency by integrating renewables into companies’ supply-networks has now been extended to account for the dynamic consideration of variable supply and demand over the year, for uncertainties related to products’ demand and sun radiation, and for multi-objective optimisation, in order to obtain the most sustainable company’s supply-network. The sustainable synthesis of a company’s network is performed regarding the integration of the renewables such as biomass and other wastes, and solar energy. The obtained solutions are those reflecting maximal profit, reflecting constantly-changing dynamic market conditions, accounting for several uncertain parameters, and protecting the environment.
Keywords: Company's supply network, Renewables, Environmental Impacts, Dynamic synthesis, Flexibility, Multi-objective optimisation, Uncertainty
Published: 21.07.2017; Views: 923; Downloads: 117
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Optimization of machining parameters for turning operation with multiple quality characteristics using Grey relational analysis
Franko Puh, Zoran Jurković, Mladen Perinic, Miran Brezočnik, Stipo Buljan, 2016, original scientific article

Abstract: Optimization of machining processes is essential for achieving of higher productivity and high quality products in order to remain competitive. This study investigates multi-objective optimization of turning process for an optimal parametric combination to provide the minimum surface roughness (Ra) with the maximum material-removal rate (MRR) using the Grey–Based Taguchi method. Turning parameters considered are cutting speed, feed rate and depth of cut. Nine experimental runs based on Taguchi’s L9 (34) orthogonal array were performed followed by the Grey relational analysis to solve the multi- response optimization problem. Based on the Grey relational grade value, optimum levels of parameters have been identified. The significance of parameters on overall quality characteristics of the cutting process has been evaluated by the analysis of variance (ANOVA). The optimal parameter values obtained during the study have been validated by confirmation experiment.
Keywords: ANOVA, Grey relational analysis, multi-objective optimization, Taguchi method, turning
Published: 12.07.2017; Views: 570; Downloads: 318
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