Price of Fairness on Networked Auctions

We consider an auction design problem under network flow constraints. We focus on pricing mechanisms that provide fair solutions, where fairness is defined in absolute and relative terms. The absolute fairness is equivalent to “no individual losses” assumption. The relative fairness can be verbalized as follows: no agent can be treated worse than any other in similar circumstances. Ensuring the fairness conditions makes only part of the social welfare available in the auction to be distributed on pure market rules. The rest of welfare must be distributed without market rules and constitutes the so-called price of fairness. We prove that there exists the minimum of price of fairness and that it is achieved when uniform unconstrained market price is used as the base price. The price of fairness takes into account costs of forced offers and compensations for lost profits. The final payments can be different than locational marginal pricing. That means that the widely applied locational marginal pricing mechanism does not in general minimize the price of fairness

Application of open multi-commodity market data model on the communication bandwidth market, Journal of Telecommunications and Information Technology, 2007, nr 4

In the paper the market model for balancing communication bandwidth trade (BCBT) is analyzed in the form of multi-commodity market data model (M3). The distinguishing feature of BCBT model is that it assumes that market players can place buy offers not only for isolated network resources – inter-node links, but also for end-to-end network paths of predefined capacity, that is, every offer concerns a point-to-point bandwidth connection between a pair of specified locations in a communication network. The model enables effective balancing of sell and buy offers for network resources in a way which maximizes global economic welfare. The open multi-commodity market data model provides efficient and clear mechanisms, which support the environment of auctions and multi-commodity exchanges, especially when the trade is constrained by the infrastructure resources. Thus the model may be used in designing open information systems for market balancing and clearing in the context of multicommodity trade in various network infrastructure sectors

Price of Fairness on Networked Auctions

We consider an auction design problem under network flow constraints. We focus on pricing mechanisms that provide fair solutions, where fairness is defined in absolute and relative terms. The absolute fairness is equivalent to "no individual losses" assumption. The relative fairness can be verbalized as follows: no agent can be treated worse than any other in similar circumstances. Ensuring the fairness conditions makes only part of the social welfare available in the auction to be distributed on pure market rules. The rest of welfare must be distributed without market rules and constitutes the so-called price of fairness. We prove that there exists the minimum of price of fairness and that it is achieved when uniform unconstrained market price is used as the base price. The price of fairness takes into account costs of forced offers and compensations for lost profits. The final payments can be different than locational marginal pricing. That means that the widely applied locational marginal pricing mechanism does not in general minimize the price of fairness

Optymalizacja struktury procesów rynkowych

Tyt. z nagłówka.Bibliogr. s. 351.Dostępny również w formie drukowanej.STRESZCZENIE: W pracy przedstawiono propozycję wielokryterialnego dyskretno-ciągłego modelu optymalizacji struktury procesów rynkowych. Po przedstawieniu ogólnego sformułowania problemu rozważono możliwości wygodnego dostosowania go przez projektanta do konkretnych systemów rynkowych. Przeanalizowano również możliwości odkrywania i modelowania preferencji projektanta przy zastosowaniu metody punktu odniesienia. Wszystkie rozważania szczegółowe zostały przeprowadzone na przykładzie rynku energii elektrycznej. SŁOWA KLUCZOWE: harmonogramowanie, procesy rynkowe, rynek energii. ABSTRACT: The proposition of multi-criteria mixed-integer optimization model for various market processes' structure is discussed. First we present general formulation of the model and next we consider the possibilities of convenient model adaptation to the specific market systems. We also analyze the possibilities of modelling market developer's preferences using the reference point method. All detailed issues are presented using a power market example. KEYWORDS: scheduling, market processes, power market

Alokacja kosztów bez subsydiowania w grach kooperatywnych opartych na programowaniu liniowym

Tyt. z nagłówka.Bibliogr. s. 340-341.Dostępny również w formie drukowanej.STRESZCZENIE: Rozważamy teoriogrowy model problemu alokacji kosztów, dla którego rdzeń modelowanej gry jest pusty. Wówczas wyznaczenie alokacji wolnej od subsydiowania wymaga relaksacji warunków na dokładny podział całkowitych kosztów. Alokacja taka może być wyznaczona jako rozwiązanie zadania optymalizacji wielokryterialnej MASIT, przy zastosowaniu wyrównująco racjonalnej relacji preferencji. Jak pokazaliśmy w eksperymentach obliczeniowych, uzyskany model może być efektywnie rozwiązywany techniką generacji kolumn. SŁOWA KLUCZOWE: alokacja kosztów, gry kooperatywne, LP-games. ABSTRACT: We consider a game theory model for cost allocation problem with empty core. In that case, a subsidy-free cost allocation involves relaxation the condition for full cost recovery. Such an allocation can be computed by solving multicriteria optimization task MASIT with equitable rational preference relation. As we present in our computational results, the allocations can be efficiently computed by column generation technique. KEYWORDS: cost allocation, cooperative games, LP-games

Modeling Multi-commodity Trade Information Exchange Methods

Market mechanisms are entering into new fields of economy, in which some constraints of physical world, e.g. Kirchoffs Law in power grid, must be taken into account during trading. On such markets, some of commodities, like telecommunication bandwidth or electrical energy, appear to be non-storable, and must be exchanged in real-time. On the other hand, the markets tend to react at shortest possible time, so an idea to delegate some competency to autonomous software agents is very attractive. Multi-commodity mechanism addresses the aforementioned requirements. Modeling the relationships between the commodities allows to formulate new, more sophisticated models and mechanisms, which reflect decision situations in a better manner. Application of multi-commodity approach requires solving several issues related to data modeling, communication, semantics aspects of communication, reliability, etc. This book answers some of the questions and points out promising paths for implementation and development. Presented solutions are based on Multi-commodity Market Model (M3 ), which enables modeling of rich variety of possible market designs. The book contains revised versions of papers presented during scientific workshop “Modeling Multi-commodity Trade: Information exchange methods", which took place in November 2010 at Warsaw University of Technology

Analysis of Demand Side Response potential in energy clusters

The paper analyses the possibilities of Demand Side Response (DSR) applications from the point of view of an electricity power cluster. Three possible scenarios for DSR mechanisms that facilitate balancing the cluster in short horizon were formulated. Two scenarios include shifting a part of demand that creates unplanned balancing energy in the cluster. In the first scenario, the unplanned balancing energy is moved to hours with lowerprices on the Balancing Market (BM), while in second scenarios we assume that this energy is bought on the competitive market. The third scenario concerns mitigation of investment cost for local distributed resources (DERs) due to DSR program. We present an analysis of monetary savings that has been carried out for exemplary clusters in Polish electrical energy system and based on Polish Balancing Market and Power Exchange data. Although the potential savings per household are too small to create strong incentives for DSR, this amount of money could be notable for the local community as a whole. There is also a big opportunity for increasing the benefits resulting from DSR in case of perceived stronger differentiation of unbalanced prices on BM as well as strong trend for price increase. We believe that presented results may play an important role to draw the potential development directions for national power clusters

Restriction techniques for the unit-commitment problem with total procurement costs

Many discrete optimization problems may be solved much easier, if the solution space can be restricted in a convenient way. For a given specific problem, the restriction techniques can be helpful if an available optimization solver, perceived as a black box, is capable of solving quickly only reduced subproblems of a limited size. For the family of hard unit-commitment problems we investigate a hierarchical search algorithm, which is based on decomposition of the problem into two subproblems. The upper-level subproblem is a relatively small decision "kernel" of the problem that can be solved approximately by a search algorithm. We define an appropriate restricted decision space for this subproblem. The lower-level subproblem is an appropriate restriction of the original problem that can be solved efficiently by a dedicated solver. Our approach was analyzed on a set of historical data from the Polish electrical balancing market and the best known solutions were improved by the average of about 2-5%.

Czynniki ryzyka wystąpienia dolegliwości bólowych odcinka lędźwiowego kręgosłupa w grupie zawodowej pielęgniarek oddziału ratunkowego

Cel: Oszacowanie częstości i czynników ryzyka występowania dolegliwości bólowych kręgosłupa lędźwiowego u czynnych zawodowo pielęgniarek krakowskich oddziałów ratunkowych. Materiał i metody: Badania przeprowadzono wśród 30 losowo wybranych, czynnych zawodowo pielęgniarek oddziału ratunkowego, w wieku 25-58 lat, pracujących na pełny etat. Obliczono wskaźnik masy ciała BMI. Wykonano pomiary linijne zakresów ruchomości odcinka lędźwiowego kręgosłupa. Do oceny stopnia subiektywnych odczuć bólowych wykorzystano wizualno-analogową skalę VAS. Stan funkcjonalny badanych oceniono Kwestionariuszem Niepełnosprawności Bólu Krzyża Roland- Morrisa (RMDQ). Do oceny poziomu aktywności fizycznej wykorzystano Międzynarodowy Kwestionariusz Aktywności Fizycznej (IPAQ). W celu określenia korelacji pomiędzy badanymi zmiennymi użyto współczynnika korelacji liniowej Spearmana. Wyniki: Wykazano statystycznie istotną zależność pomiędzy BMI a poziomem bólu oraz stopniem niesprawności wyrażoną na podstawie kwestionariusza RMDQ a także pomiędzy poziomem bólu a czasem spędzanym w pozycji siedzącej. Zanotowano istotny związek pomiędzy stopniem odczuć bólowych a zgięciem kręgosłupa w płaszczyźnie strzałkowej, zgięciem bocznym w prawo w płaszczyźnie czołowej i skrętem w prawo w płaszczyźnie poprzecznej. Wnioski: Dolegliwości bólowe kręgosłupa wśród pielęgniarek oddziału ratunkowego są zjawiskiem częstym, określonym na poziomie średnim, powodującym niewielki ubytek jakości życia. Zaobserwowano wysoki stopień aktywności fizycznej oraz zmniejszony zakres zgięcia w płaszczyźnie strzałkowej. Ze względu na istniejące korelacje pomiędzy BMI a poziomem bólu i stopniem niesprawności oraz poziomem bólu a zakresami ruchomości wydaje się celowe objęcie tej grupy zawodowej programem profilaktyki bólu kręgosłupa.Aim of the study: To assess prevalence and risk factors of low back pain (LBP) in emergency room nurses in Krakow. Materials and methods: The study comprised 30 randomly selected full time emergency nurses aged 25-58. Their BMI was calculated and measurements of linear segmental lumbar spine flexion-extension motion were performed. The visual analogue scale (VAS) was used to assess the subjective LBP degree. The self-estimated physical disability caused by LBP was assessed by means of the Roland- Morris Low Back Pain and Disability Questionnaire (RMDQ), whereas physical activity by means of the International Physical Activity Questionnaire (IPAQ). The Spearman correlation coefficient was used to determine a linear association between variables involved in the research. Results: Statistically significant correlations between BMI, LBP and the level of disability as well as between the pain intensity and the time spent in a sitting position were revealed by RMDQ. Significant correlations between the self-estimated LBP and spinal flexion in the sagittal plane, lateral flexion to the right in the frontal plane and twist to the right in the transverse plane were found. Conclusions: Moderate LBP in emergency ward nurses, which is commonly observed, slightly decreased their quality of life. A high level of physical activity and limited range of flexion were discovered in the sagittal plane. Due to the existing correlations between BMI and LBP, between the degree of disability and the intensity of pain and the range of motion, it seems appropriate to include this occupational group in the back pain prevention programme