Robust ordinal regression in preference learning and ranking

Multiple Criteria Decision Aiding (MCDA) offers a diversity of approaches designed for providing the decision maker (DM) with a recommendation concerning a set of alternatives (items, actions) evaluated from multiple points of view, called criteria. This paper aims at drawing attention of the Machine Learning (ML) community upon recent advances in a representative MCDA methodology, called Robust Ordinal Regression (ROR). ROR learns by examples in order to rank a set of alternatives, thus considering a similar problem as Preference Learning (ML-PL) does. However, ROR implements the interactive preference construction paradigm, which should be perceived as a mutual learning of the model and the DM. The paper clarifies the specific interpretation of the concept of preference learning adopted in ROR and MCDA, comparing it to the usual concept of preference learning considered within ML. This comparison concerns a structure of the considered problem, types of admitted preference information, a character of the employed preference models, ways of exploiting them, and techniques to arrive at a final ranking

Analysis of the bus maintenance process on the basis of chosen operator of public transport

Pokazano możliwości analizy procesów eksploatacji pojazdów metodami modelowania i symulacji komputerowej na przykładzie pojazdów eksploatowanych przez operatora transportu autobusowego. Opracowano model matematyczny stanów eksploatacyjnych autobusu. Opisano symulator komputerowy służący do ułatwienia badań prowadzonych za pomocą tego modelu. Sformułowano przykładowe problemy badawcze i podano wyniki ich rozwiązania.This paper presents the possibilities for analysing, through modeling and computer simulation, the maintenance of vehicles maintained by a bus transport operator. The paper details a mathematical model of bus maintenance states. The paper also describes a computer simulator that was created in order to simplify the application of the mathematical model. Examples of some problems and their solutions are defined

Procedura wyznaczania początku starzenia się obiektów na podstawie monitorowania empirycznej funkcji intensywności uszkodzeń

The estimation of the number of failures of technical objects is of key importance throughout the object life cycle, particularly in the wear-out period when the number of failures begins to grow significantly. In the literature related to this problem, examples exist of solutions (mathematical models) that can assist the estimation of the number of failures. For the description of the life cycles of objects, functions are usually used of known forms of probability distribution of the number of object failures. The procedure presented in this paper assumes the use of statistical data related to the failures of uniform population of nonrenewable technical objects, recorded in the form of empirical function of failure intensity. It specifically serves the purpose of determining the characteristic point of life of these objects i.e. the onset of the wear-out period. Within the procedure, a model of fuzzy inference has been applied that reflects the human reasoning (expert of the system) observing/investigating the objects. The results of the developed procedure may constitute a basis for forecasting of failures of mechanical nonrenewable technical objects.Oszacowanie liczby uszkodzeń obiektów technicznych ma kluczowe znaczenie we wszystkich okresach cyklu życia obiektów, szczególnie w okresie uszkodzeń starzeniowych, kiedy to liczba uszkodzeń zaczyna znacząco rosnąć. W bibliografii tego zagadnienia przytoczone są przykłady rozwiązań (modeli matematycznych), którymi można wspomagać m.in. szacowanie liczby uszkodzeń. Do opisu cyklu życia obiektów technicznych wykorzystuje się zwykle funkcje o znanych postaciach rozkładów prawdopodobieństwa liczb uszkodzeń tych obiektów. Przedstawiona w niniejszym artykule procedura, zakłada korzystanie ze statystycznych danych o uszkodzeniach jednorodnej zbiorowości nieodnawianych obiektów technicznych, zapisanych w postaci empirycznej funkcji intensywności uszkodzeń. Służy ona w szczególności do wyznaczenia charakterystycznego punktu życia tych obiektów tj. chwili rozpoczynania się okresu uszkodzeń starzeniowych. W ramach procedury zastosowano model wnioskowania rozmytego, który odwzorowuje rozumowanie człowieka (eksperta systemu) obserwującego/badającego obiekty. Wyniki opracowanej procedury mogą stać się podstawą prognozowania uszkodzeń nieodnawianych obiektów technicznych typu mechanicznego

Hazard record

Artykuł dotyczy ważnego kroku algorytmu metod zarządzania ryzykiem zagrożeń – realizacja procesu identyfikacji zagrożeń i przygotowanie rejestru zagrożeń. Rejestr zagrożeń jest ostatecznym rezultatem procesu identyfikacji zagrożeń. Zaprezentowano sposób pozyskiwania informacji do tworzenia rejestrów zagrożeń i propozycję ich formatu. Na tle formatu rejestru podano wytyczne / rekomendacje do wypełniania pól kart charakterystyki pojedynczego zagrożenia składających się na rejestr zagrożeń.This paper deals with an important step of the risk management methods – implementation of the hazard identification process (HIP) and preparation of the hazard record (HR). The HR is a final result of the HIP. We present the way of gathering information for preparing the HR and some forms of the record. Referring to the HR format, we provide the guidelines / recommendations for filling in the fields of a hazard data sheet concerning a single hazard

The concept of identification of layers of safety system models through classification of risk reduction measures

The article is an introduction to the analysis of the functioning of the safety systems with the use of layered models. The idea behind these models is the classification of elements of safety systems into independent groups referred to as the layers of protection. It seems that the functioning of the safety systems is usually based on the concept of multi-layer securities. Modern technological installations of high-risk industrial facilities are fitted with multi layer security systems. The definition of the safety systems and a review of the definitions of hazard risk reduction measures as part of those systems are presented. A layer of the model of a safety system comprises the measure of risk reduction in terms of the stage of classification. It has been assumed that the safety system model will depend on the adopted classification of these measures. The classification of risk reduction measures used in safety systems of technical objects depending on the form of these measures is presented. Assuming that the form of the safety system model depends on the adopted classification of the risk reduction measures we can perform an identification of the layers of this model. The concept of identification of protection layers in multi-layers safety systems based on classifications is developed. The notation used in the classification of types of risk reduction measures is also presented. Schematic of safety system identification of transport systems objects according to the adopted classification of types of risk reduction measures is developed. According to these schematics, we can describe the safety system models of object other than those related to transport. An example of such an adaptation has been developed for a multi-layer safety system model of objects in the processing industry

Systemic approach and model of the Polish Tactical Air Force

The main purpose of this article is to present the structure of a tactical air force, on the example of the Polish Tactical Air Force, in a form of a technical system. This kind of technical system presents the technical point of view and organizationally bonds currently existing systems, objects (facilities) and components that are included into the Polish Tactical Air Force. The authors consider the Polish Tactical Air Force as the main analyses domain of this article. The model of presented system is mainly focused on operators’ organization and operation system of military aircraft, which are considered as technical objects (facilities) in a tactical air force. At the beginning of this article, the Polish Tactical Air Force is placed in more complex systemic structures. Then, the authors use the systems methodology, systems engineering, technical object-oriented (facility-oriented) approach and the matrix of the Model of Generalized Technical System to describe the Tactical Air Force System and present it via the model of such a system. The following model is based on a tree-shaped scheme divided into five levels of decomposition. The Model of Tactical Air Force System (as the “final product” of authors’ considerations over the selected analyses domain) has a considerable contribution to systems’ development in the Polish Armed Forces. The above-mentioned systems’ development could lead to greater progress in the Polish military as well as in systemic ideas. The implementation of the systems methodology in the design process of a new system, performed in a tactical air force, is an example of technical object systems engineering

Railway level crossings in Estonia – classification and requirements for safety systems

W artykule przedstawiono zasady i przepisy zawarte w podstawowych aktach prawnych dotyczących przejazdów i przejść kolejowych w Estonii. Podano zasady kwalifikacji przejazdów do jednej z trzech kategorii oraz wymagane elementy systemu bezpieczeństwa dla każdej z nich. Omówiono wymagania dotyczące znaków drogowych, sygnalizatorów i urządzeń rogatkowych stosowanych na estońskich przejazdach kolejowych.In the article principles and provisions of the essential legal acts on level crossings in Estonia are presented. The principles of qualification of level crossings into one of three categories are provided along with required elements of safety system used for each of the categories. Requirements for traffic signs, signals and barriers used on Estonian level crossings are presented

Management of risks associated with pedestrians in the area of the main railway station in Poznan

Obszarem analiz w tym artykule jest węzeł komunikacyjny Poznań Główny. Na podstawie wybranego przystanku zaprezentowano procedury: rozpoznawania źródeł zagrożeń, grupowania źródeł zagrożeń, formułowania zagrożeń, szacowania ryzyka zagrożeń i wartościowania ryzyka. Są to jedne ze szczegółowych procedur analizy ryzyka w modelu TRANS-RISK. Wykazano ważność tych procedur w zarządzaniu ryzykiem zagrożeń na przykładzie węzła komunikacyjnego Poznań Główny.The main railway station in Poznan (Poznan Główny) is a major transportation hub in the city and therefore it can be used as a valuable area for risk assessment. One of the tram stops located within the hub has been used to perform four main procedures used in TRANS-RISK model: recognition of threats' sources, grouping of threats' sources, formulation of threats and valuation of risk. The procedures have been described and their importance has been proved

Hazard identification process in the selected analysis domain of the F100 turbofan engines maintenance system

The multirole F-16 is the most advanced aircraft in the Polish Air Forces. It has been equipped with the very modern, sophisticated and advanced turbofan engine F100-PW-229. Due to the fact, that there is only one engine, its reliability, durability efficiency and performance are the crucial factors for the safety reasons. In the article authors researched maintenance system of the F100 turbofan engines, which are built on the multirole F-16 aircraft. For the study purposes F100 maintenance system model has been created. From this model, the main analysis domain was derived, comprising “Major engine objects discrepancies removal” process. Considering such an analysis domain, on the basis of the schematic diagram of the hazard identification process, authors presented the following procedures: tools preparation for the hazard sources identification, hazard sources identification, hazard sources grouping and hazards formulation. The main goal of this article was to provide hazard identification process results as hazard specifications, which include: a group of hazard sources, hazards formulation and the most probable/predictable consequences, severities and losses/harms of the hazard activation