Finland is among the countries with the highest amount of English-taught programmes in higher education in Europe (Wächter and Maiworm 2008). This article analyses, how the higher education language situation of a small country with a... more
Finland is among the countries with the highest amount of English-taught programmes in higher education in Europe (Wächter and Maiworm 2008). This article analyses, how the higher education language situation of a small country with a marginal majority language (Finnish) and an official bilingual status (Finnish and Swedish) has historically developed from the setting of “drawing the line” between Finland and Sweden or Finland and Russia (Harle and Moisio 2000) in the 19th century and the early 20th century (nationalism), towards drawing the line between Finnish/Swedish and English in the late 20th century (globalization). It then continues to present a case of foreign language (in practice English) programmes in higher education as an example of the globalization development in Finnish higher education. The data for the article consists of the internationalization strategies for Finnish higher education, The Finnish International Study Programme Database, and introductory texts fro...
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The short term scheduling of a national energy production for one week time horizon is considered. The problem is to optimize the use of various kinds of power plants such as nuclear power, conventional condensing power, counter pressure... more
The short term scheduling of a national energy production for one week time horizon is considered. The problem is to optimize the use of various kinds of power plants such as nuclear power, conventional condensing power, counter pressure power and water power. Energy storages are also included in the optimization.
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This study is about multicriteria decision aiding (MCDA) for the green airports program of the Moroccan Airport Authority ONDA. The goal of the program is to develop significant amounts of renewable power at airports. In particular, ONDA... more
This study is about multicriteria decision aiding (MCDA) for the green airports program of the Moroccan Airport Authority ONDA. The goal of the program is to develop significant amounts of renewable power at airports. In particular, ONDA wants to select airports at which large solar and wind power parks should be built. Multiple criteria, including economy, technical feasibility, and environmental concerns, must be considered simultaneously. In this study, we apply Stochastic Multicriteria Acceptability Analysis (SMAA) for ranking the candidates to be developed into green airports. The analysis is conducted in phases with different sets of criteria. This study is the first application of MCDA for developing large-scale renewable energy production at airports. As a theoretical novelty, the pairwise winning indices of SMAA are used to form stochastic partial and complete rankings of the alternatives. Based on the results, two alternatives obtain the best and second-best rank in every ...
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Modern decision making problems are discrete and multicriteria by nature, and involve several decision makers (DMs). One of the key questions in this type of problems is how the preferences of the DMs can be modelled. Usually the DMs are... more
Modern decision making problems are discrete and multicriteria by nature, and involve several decision makers (DMs). One of the key questions in this type of problems is how the preferences of the DMs can be modelled. Usually the DMs are not sure of their preferences or will not tell them to the analyst, because they are not able to express their preferences directly. In these type of situations the decision support system should allow modelling of ignorance. Stochastic Multicriteria Acceptability Analysis (SMAA) is a family of methods to aid DMs in discrete decision aiding problems. Dempster-Shafer theory of evidence (DST) allows modelling of ignorance by using belief functions. In this paper we show how the preferences of multiple DMs or other stakeholders can be modelled and combined using DST, and how this information can then be encoded as interval constraints for sets of weights in SMAA. Our contribution has a wide range of practical applications. We present a real-world case ...
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This study proposes to use gas-fired boilers as peak shaving heat sources in heating substations due to their capability to increase the reliability, flexibility and heat capacity without the need to change the district heating network... more
This study proposes to use gas-fired boilers as peak shaving heat sources in heating substations due to their capability to increase the reliability, flexibility and heat capacity without the need to change the district heating network (DHN). However, the design and operational requirements with different connection modes for this kind of DH system are still not clear. This paper presents a systematic study on this kind of DH system, analyzes the connection modes of series and parallel connections between the gas-fired boilers and the heat exchangers. For each connection mode, we figured out the thermal balances and obtained the design and operational parameters including the supply temperatures of the heat exchangers, gas-fired boilers and their variations under different network temperature levels and the base load ratios (β). Under the series connection mode, the design supply temperature of the heat exchangers has no relation with the design peak shaving flow ratio (ω’); it decr...
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ABSTRACT Plate heat exchangers (PHE) have consolidated their position as key components of modern heating processes. They are widely accepted as the most suitable design for heat transfer applications in various processes, including the... more
ABSTRACT Plate heat exchangers (PHE) have consolidated their position as key components of modern heating processes. They are widely accepted as the most suitable design for heat transfer applications in various processes, including the field of energy-efficient district heating (DH). This study refers to new DH coupling and control applied to a consumer substation. The concept introduces a new mass flow control model optimising the primary and secondary water streams to achieve remarkably higher temperature cooling in a new low temperature programme with diminished pressure losses. Here the operation of the ring network and the mass flow control in the substation are studied theoretically. A calculation procedure and transient models were constructed for the DH network, building structures, and heating heat exchangers. The PHE and its operation in the substation were studied by means of a corrugated plate model with five vertical parts and 10 elements. Variations in the flow rates, pressure losses, and overall heat transfer coefficients were received for the selected days. As a result almost equal heat capacity flows were found between the hot and cold sides of the PHE with maximum temperature cooling. The key performance factors of the heat exchanger, NTU and effectiveness, were monitored and the mean values obtained were 9.2 and 0.9, respectively.
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Stochastic multicriteria acceptability analysis (SMAA) is a ,family of methods for aiding multicriteria group decision making. These methods are based on exploring the weight space in order todescribe the preferencesthat make each... more
Stochastic multicriteria acceptability analysis (SMAA) is a ,family of methods for aiding multicriteria group decision making. These methods are based on exploring the weight space in order todescribe the preferencesthat make each alternative the most preferred one, or thatgiv ea certain rank for a specific alternative. The mainresults of the analysisare rank acceptability
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... Risto Lahdelma a , E-mail The Corresponding Author and Pekka Salminen b , Corresponding Author Contact Information , E-mail The Corresponding Author. ... P is not based on a utility or value function model; instead the DMs preferences... more
... Risto Lahdelma a , E-mail The Corresponding Author and Pekka Salminen b , Corresponding Author Contact Information , E-mail The Corresponding Author. ... P is not based on a utility or value function model; instead the DMs preferences are represented in the spirit of prospect ...
Research Interests: Marketing, Set Theory, Statistical Analysis, Stochastic analysis, Decision support system, and 11 moreOMEGA, Prospect Theory, Business and Management, Group Decision Making, Piecewise Linear, Incomplete Information, Decision Support, Imperfect information, Decision Problem, Decision Maker, and Probability Distribution
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Stochastic multi-criteria acceptability analysis (SMAA) is a multi-criteria decision support method for multiple decision-makers (DMs) in discrete problems. SMAA does not require explicit or implicit preference information from the DMs.... more
Stochastic multi-criteria acceptability analysis (SMAA) is a multi-criteria decision support method for multiple decision-makers (DMs) in discrete problems. SMAA does not require explicit or implicit preference information from the DMs. Instead, the method is based on exploring the weight space in order to describe the valuations that would make each alternative the preferred one. Partial preference information can be represented in the weight space analysis through weight distributions. In this paper we compare two variants of the SMAA method using randomly generated test problems with 2–12 criteria and 4–12 alternatives. In the original SMAA, a utility or value function models the DMs' preference structure, and the inaccuracy or uncertainty of the criteria is represented by probability distributions. In SMAA-3, ELECTRE III-type pseudo-criteria are used instead. Both methods compute for each alternative an acceptability index measuring the variety of different valuations that supports this alternative, and a central weight vector representing the typical valuations resulting in this decision. We seek answers to three questions: (1) how similar are the results provided by the decision models, (2) what kind of systematic differences exists between the models, and (3) how could one select indifference and preference thresholds of the pseudo-criteria model to match a utility model with given probability distributions?
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ABSTRACT District heating (DH) systems are an inseparable part of the infrastructure in many countries. Today more attention is being paid to energy savings, efficiency improvements, and the replacement of fossil fuels by renewable... more
ABSTRACT District heating (DH) systems are an inseparable part of the infrastructure in many countries. Today more attention is being paid to energy savings, efficiency improvements, and the replacement of fossil fuels by renewable energy. Research in the field of DH is focused on the supply of areas with low heat demand and low-energy buildings and on an increased share of heat being produced from renewable energy sources. New DH systems are expected to remain competitive in the future. In this study a new DH concept is proposed which is based on mass flow control. The DH system using mass flow control is meant for the concept of a ring network technology where mass flow rates in consumer substations are controlled by pumps with inverters to improve heat transfer. It will replace the traditional DH network and control in which water flow is throttled by control valves. The new control system will enable new temperature curves to be adopted for supply and return temperatures and more significant temperature cooling. First, a new topology and control method is presented. This ring network and the method used to control the flow rate of the primary supply water and its temperature are compared with the traditional technology. This method clearly shows the benefits of the DH applications under consideration. Second, these benefits are demonstrated by mathematical modelling. A simulation model is developed to study the area heating of six single-family houses and two apartment buildings. The static operation on the primary side of the networks is investigated for the most common outdoor temperatures. The numerical results are compared to those achieved with the traditional technology. The new flow rate is 46%, the pressure loss 25%, and the pumping power 12% of their former values in the pipes. The heat losses increase slightly with higher outdoor temperatures. The return temperature is lowest with the new technology. In the future the equipment that consumers will have will be more intelligent. The new technology that is presented allows consumers to adjust their energy consumption more easily by means of fast feedback on outdoor and room temperatures.
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A sustainable energy system is an integrated approach to supplying local energy demands from renewable energy or/and high-efficiency polygeneration energy sources. The approach can be seen as a development of the distributed generation... more
A sustainable energy system is an integrated approach to supplying local energy demands from renewable energy or/and high-efficiency polygeneration energy sources. The approach can be seen as a development of the distributed generation concept. The main characteristics of a sustainable energy system are (cost) efficiency, reliability and environmentalfriendliness. In this paper, we mainly discuss the role of the polygeneration in a distributed energy system and contributions of polygeneration in the sustainable energy system development. We also describe the characteristics of polygeneration plants to highlight the complexity of polygeneration technologies. In addition, we review the typical method for dealing with interdependence between different energy products for polygeneration and point out some practices in the industry may prevent the potential of polygeneration into full play. Keywords— polygeneration; energy efficiency; distributed energy system; sustainable energy system.
A framework for a multi-attribute multi-source data fusion is described. Uncertainty of data is modeled by fuzzy sets. The problem is considered on a general level. Credibility of sources, compatibility of data, as well as their... more
A framework for a multi-attribute multi-source data fusion is described. Uncertainty of data is modeled by fuzzy sets. The problem is considered on a general level. Credibility of sources, compatibility of data, as well as their reasonableness, are taken into consideration. The proposed method is illustrated by an example.
ELECTRE III is a well-established multiple criteria decision making method with a solid track of real-world applications. It requires precise values to be specified for the parameters and criteria measurements, which in some cases might... more
ELECTRE III is a well-established multiple criteria decision making method with a solid track of real-world applications. It requires precise values to be specified for the parameters and criteria measurements, which in some cases might not be available. In this paper we present a method, SMAA-III, that allows ELECTRE III to be applied with imprecise parameter values. By allowing imprecise values, the method also allows an easily applicable robustness analysis. In SMAA-III, simulation is used and descriptive measures are computed to characterize stability of the results. We present a software implementing the method and show the usage by re-analyzing an existing case study.
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The basic regulation formula (RF) based on direct-connection DH system is widely used to operate the DH systems, but the formula maybe not suitable for indirectconnection DH system. Here indirect connection means that the working fluid... more
The basic regulation formula (RF) based on direct-connection DH system is widely used to operate the DH systems, but the formula maybe not suitable for indirectconnection DH system. Here indirect connection means that the working fluid circulated in CHP and the primary network is not the same medium that flows in the secondary network. Therefore, this paper deduces the regulation formula for indirect-connection DH system. According to accuracy analysis, we find that the applicability of the regulation formula should be based on three conditions: 1) The design indoor temperature and volume specific heat load of all buildings are the same; 2) The same type of heating devices are used in the buildings after each substation or all heating devices are deemed as a big radiator with average performance; 3) The supply and return water temperatures in primary and secondary sides are the same for each substation. If the three conditions cannot hold true at the same time, then the accuracy of ...
Abstract—High penetration of intermittent renewable energy sources (RES) such as solar power and wind power into the energy system has caused temporal and spatial imbalance between electric power supply and demand for some countries and... more
Abstract—High penetration of intermittent renewable energy sources (RES) such as solar power and wind power into the energy system has caused temporal and spatial imbalance between electric power supply and demand for some countries and regions. This brings about the critical need for coordinating power production and power exchange for different regions. As compared with the poweronly systems, the combined heat and power (CHP) systems can provide additional flexibility of utilizing RES by exploiting the interdependence of power and heat production in the CHP plant. In the CHP system, power production can be influenced by adjusting heat production level and electric power can be used to satisfy heat demand by electric boiler or heat pump in conjunction with heat storage, which is much cheaper than electric storage. This paper addresses multi-site CHP systems without considering RES, which lay foundation for handling penetration of RES. The problem under study is the unit commitment ...
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We have developed a multicriteria decision aiding method for nominal classification for situations where prefer-ence information is imprecise, uncertain or absent. Such situations may appear, for instance, when the decisionmaker is not... more
We have developed a multicriteria decision aiding method for nominal classification for situations where prefer-ence information is imprecise, uncertain or absent. Such situations may appear, for instance, when the decisionmaker is not sure about his or her preferences or when there are multiple decision makers who have difficulties inagreeing about their common preference. The new SMAA-Classification method extends Stochastic Multicrite-ria Acceptability Analysis (SMAA) methodology for classification problems. The method provides the decisionmaker with descriptive information in the form of acceptability index for each alternative to be classified intoeach predefined class. We test the new method with several applications.
Modern decision making problems are discrete and multicriteria by nature, and involve several decision makers (DMs). One of the key questions in this type of problems is how the preferences of the DMs can be modelled. Usually the DMs are... more
Modern decision making problems are discrete and multicriteria by nature, and involve several decision makers (DMs). One of the key questions in this type of problems is how the preferences of the DMs can be modelled. Usually the DMs are not sure of their preferences or will not tell them to the analyst, because they are not able to express their preferences directly. In these type of situations the decision support system should allow modelling of ignorance. Stochastic Multicriteria Acceptability Analysis (SMAA) is a family of methods to aid DMs in discrete decision aiding problems. Dempster-Shafer theory of evidence (DST) allows modelling of ignorance by using belief functions. In this paper we show how the preferences of multiple DMs or other stakeholders can be modelled and combined using DST, and how this information can then be encoded as interval constraints for sets of weights in SMAA. Our contribution has a wide range of practical applications. We present a real-world case ...
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Key stakeholders in industry are highly responsible for achieving energy performance targets. Particularly, this paper assesses the attitudes, approaches, and experiences of Finnish construction professionals regarding energy-efficient... more
Key stakeholders in industry are highly responsible for achieving energy performance targets. Particularly, this paper assesses the attitudes, approaches, and experiences of Finnish construction professionals regarding energy-efficient buildings, or nZEBs. A three-tier investigation was conducted including surveys and expert interviews with several stakeholders. The structure of this approach was informed by preliminary data and information available on the Finnish construction sector. The questionnaire showed that the stakeholders ranked energy efficiency and embodied energy/carbon as very important. The survey highlighted that the importance of the embodied carbon CO2 in the materials is less important than the energy efficiency from many of the stakeholders’ points of view. “Energy efficiency” is very important for ESCOs, contractors, and facility managers followed by architects, HVAC engineers, and construction design engineers. Nevertheless, the opinions of architects ranked “e...
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Renewable energy sources (RES) are playing an increasingly important role in energy markets around the world. It is necessary to evaluate the benefits from a higher level of RES integration with respect to a more active cross-border... more
Renewable energy sources (RES) are playing an increasingly important role in energy markets around the world. It is necessary to evaluate the benefits from a higher level of RES integration with respect to a more active cross-border transmission system. In particular, this paper focuses on the sustainable energy transitions for Finland and Italy, since they have two extreme climate conditions in Europe and quite different profiles in terms of energy production and demand. We developed a comprehensive energy system model using EnergyPLAN with hourly resolution for a reference year for both countries. The models include electricity, heat and transportation sectors. According to the current base models, new scenarios reflecting an RES increase in total fuel consumption have been proposed. The future shares of renewables are based on each nation’s potential. The outcomes of the new scenarios support the future national plans, showing how decarburization in an energy system can occur in ...
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SMEs play a crucial role in economies by providing large scale employment and contributing to much of the GDP. Despite their vital role, SMEs face a plethora of challenges, and often, the aspect of energy efficiency is overlooked. This... more
SMEs play a crucial role in economies by providing large scale employment and contributing to much of the GDP. Despite their vital role, SMEs face a plethora of challenges, and often, the aspect of energy efficiency is overlooked. This paper conducted studies across Finland, Switzerland, Austria, Italy, France, and Germany and devised an easy and ready-to-adopt approach to improve energy efficiency in SMEs. The new approach is based on a maturity matrix that supports continuous learning and development and provides expert recommendations on energy efficiency for SMEs around the world. The expert recommendations are based on a final score and aim to address the various challenges that SMEs face, such as limited access to knowledge and lack of awareness of energy efficiency. The approach may be easily adopted by any SME around the world.
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... RISTO LAHDELMA University of Turku, Department of Computer Science, Lemminkdisenkatu 14 A, FIN-20520 Turku, Finland, Risto.Lahdelma@cs.utu.fi ... distributions into utility distributions u(6i, w). Total lack of knowledge about weights... more
... RISTO LAHDELMA University of Turku, Department of Computer Science, Lemminkdisenkatu 14 A, FIN-20520 Turku, Finland, Risto.Lahdelma@cs.utu.fi ... distributions into utility distributions u(6i, w). Total lack of knowledge about weights is repre-sented in "Bayesian" spirit by a ...
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ABSTRACT In this paper, a new energy-efficient district heating system is examined. This system has two differences compared to the traditional network: a new control system called mass flow control and a new network topology called a... more
ABSTRACT In this paper, a new energy-efficient district heating system is examined. This system has two differences compared to the traditional network: a new control system called mass flow control and a new network topology called a ring network. Optimal district heating water temperatures for mass flow control in a low-temperature network are examined. The examination is done with a case study, where the network consists of 14 detached houses and an apartment building. The district heating network was assumed to be attached to a wood-burning heat station which has a heat recovery system in use. The analysis of the district heating network was mainly performed by using the Grades Heating calculation application. The results are promising and the total energy losses of the network are reduced. Mass flow control allows smaller pressure drops in the network and consequently reduces the pumping power that is required. Lower temperatures of district heating water are essential when reducing the heat losses involved in heat production. Lower return temperatures can be utilised by using a heat recovery system. However, an increased supply water temperature increases the average temperature and thus the heat losses in the pipes increase slightly. If the ring network design is utilised, the district heating system is easier to control. Heat losses are also reduced, according to simulations. On the basis of the results, the new district heating system studied in this paper is significantly more energy-efficient in the case network that was examined than the traditional system design. For example, average energy losses within the constraints that were examined (which consist of heat losses, pumping energy, and surplus energy from the heat recovery system) are reduced from 4.4% to 3.1%.
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Research Interests: Linear Programming, Production Planning, Production Management, Multidisciplinary, Electricity Market, and 15 moreOptimization, Power Generation, Asymmetry, Energy Optimization, Energy Production, Cost Efficiency, Energy efficient, Power Market, Electric Power, Long Term, Envelope, Simplex method, Combined Heat and Power, LINEAR PROGRAM, and Optimal Solution
Research Interests: Fuzzy Logic, Fuzzy set theory, Linear Programming, Modeling, Fuzzy Sets, and 14 moreMultidisciplinary, Optimization, Optimization Problem, Linear Model, Soft Constraints, Production Process, Chance Constraint, Fuzzy Set, Boolean Satisfiability, Chemical Composition, LINEAR PROGRAM, Aspiration Level, Confidence Interval, and Fuzzy Number
In environmental planning and decision processes several alternatives are analyzed in terms of multiple noncommensurate criteria, and many different stakeholders with conflicting preferences are involved. Based on our experience in... more
In environmental planning and decision processes several alternatives are analyzed in terms of multiple noncommensurate criteria, and many different stakeholders with conflicting preferences are involved. Based on our experience in real-life applications, we discuss how multicriteria decision aid (MCDA) methods can be used successfully in such processes. MCDA methods support these processes by providing a framework for collecting, storing, and processing all relevant information, thus making the decision process traceable and transparent. It is therefore possible to understand and explain why, under several conflicting preferences, a particular decision was made. The MCDA framework also makes the requirements for new information explicit, thus supporting the allocation of resources for the process.
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The adverse environmental consequences and diminishing trend of fossil fuel reserves indicate a serious need for vibrant and judicious energy policy. Energy policy involves a number of stakeholders, and needs to incorporate the interests... more
The adverse environmental consequences and diminishing trend of fossil fuel reserves indicate a serious need for vibrant and judicious energy policy. Energy policy involves a number of stakeholders, and needs to incorporate the interests and requirements of all the key stakeholder groups. This paper presents a methodological technique to assist with formulating, evaluating, and promoting the energy policy of a country in a transparent and representative way with clear scientific justifications and balanced assessments. The multicriteria decision analysis approach has been a widely used technique for evaluating different alternatives based on the interests of a multitude of stakeholders, and goals. This paper utilizes the SMAA (Stochastic Multicriteria Acceptability Analysis) tool, which can evaluate different alternatives by incorporating multiple criteria, in order to examine the preferences of different policy elements. We further extend this technique by incorporating the LEAP model (Long-range Energy Alternatives Planning system) to assess the emission impacts of different policy elements. We demonstrate the application of this evaluation technique by an analysis of four hypothetical policy elements namely Business-as usual (BAU), Renewables (REN), Renewable-biomass only (REN-b), and Energy conservation and efficient technologies (ECET). These are applied to the case of sharing fuel sources for power generation for the Bangladesh power sector. We found that the REN-b and REN policy elements were the best and second best alternatives with 41% and 32% acceptability respectively. This technique gives transparent information for choosing appropriate policy elements that aimed at sustainable energy.
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Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making in problems with inaccurate, uncertain, or missing information. These methods are based on exploring the weight... more
Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making in problems with inaccurate, uncertain, or missing information. These methods are based on exploring the weight space in order to describe the preferences that make each alternative the most preferred one, or that would give a certain rank for a specic alternative. The main
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Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making in problems with uncertain, imprecise or partially missing information. These methods are based on exploring the... more
Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making in problems with uncertain, imprecise or partially missing information. These methods are based on exploring the weight space in order to describe the preferences that make each alternative the most preferred one, or that would give a certain rank for a specific alternative. The
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We consider multicriteria decision-making (MCDM) problems with multiple decision makers. In such problems, the uncertainty or inaccuracy of the criteria measurements can be represented as probability distributions. In many real-life... more
We consider multicriteria decision-making (MCDM) problems with multiple decision makers. In such problems, the uncertainty or inaccuracy of the criteria measurements can be represented as probability distributions. In many real-life problems the uncertainties may be dependent. However, it is often difficult to quantify these dependencies. Also most of the existing MCDM methods are unable to handle such dependency information. In