Dariusz Skorupka

Evaluation of probability of bridge damage as a result of terrorist attack

Abstract The paper presents an approach for evaluation of the likelihood of damage to the transportation infrastructure in the context of the terrorist attacks on the example of a number of bridges located in Wrocław (Poland). Assuming that there will be only one bridge destroyed in a given area, in order to determine the probability of damage to one of the objects, there was one of multi-criteria optimization methods used, i.e. the method of Analytical Hierarchy Process (AHP). The main advantage of the analysis carried out was that the accepted hierarchy of decision-making options could be easily explained in a scientific manner, not only with reference to personal knowledge, experience, and intuition.

The Use of the Generalised Knapsack Problem in Computer Aided Strategic Management

There are many methods and tools in the literature that are helpful in strategic management. Some of them are related to the aspect of sustainability in terms of controlling and balancing the level of fulfilment of the different, sometimes conflicting, objectives which must be considered while building strategies. These tools include product portfolio methods. However, their use is often intuitive and detached from the quantitative aspects of management, such as cost-related restrictions or other quantitative restrictions imposed by the market or by internal circumstances. This article presents a proposal for the modification of portfolio methods aimed at enforcing the portfolio’s quantitative aspect through the use of a discrete optimisation problem, namely the knapsack problem. Interacting with the decision maker, the quantitative parameters of the situation and the strategic goals are determined. Following this, a proposal solution is generated by a computer system in which the respective algorithms for the generalised knapsack problem (also called the generalised assignment problem) are embedded. The decision maker can accept the solution or change the parameters if the solution does not suit them or if they simply want to have other solutions for comparison. The outline of the system and the interaction between the decision maker and the system is illustrated by means of an example of constructing strategies for a university.

Application of the AHP method in modeling the trust and reputation of software agents

Given the unique characteristics of cyberspace and, in particular, the number of inherent security threats, communication between software agents becomes a highly complex issue and a major challenge that, on the one hand, needs to be continuously monitored and, on the other, awaits new solutions addressing its vulnerabilities. An approach that has recently come into view mimics mechanisms typical of social systems and is based on trust and reputation that assist agents in deciding which other agents to interact with. The paper offers an enhancement to existing trust and reputation models, involving the application of the AHP method that is widely used for decision support in social systems, notably for risks analysis. To this end, it is proposed to expand the underlying conceptual basis by including such notions as self-trust and social trust, and to apply these to software agents. The discussion is concluded with an account of an experiment aimed at testing the effectiveness of the proposed solution.

Fuzzy analysis of project duration in situations of risk

The duration of project activities is usually not deterministic. Thus, it may be modeled by means of fuzzy numbers. In the literature there exist several fuzzy approaches to the modeling of project activities duration. In this paper a new one proposed, which will permit to determine the critical path taking into account several risk factors and expert opinions. A Finally, a case study will be presented and analysed: the project of constructing a shopping mall in Poland.

Risk assessment as a safety element in temporary bridge exploitation

The world financial crisis, which started in the real property market, suppressed voices of risk analysis critics. Most entrepreneurs do not question its necessity, however, only few of them use it in practice. The reasons for this situation include financial ones or lack of organisational culture. Risk identification in bridge facilities exploitation encompasses specification and hierarchisation of potential threats. These threats may hamper transport or even make it impossible. Correct specification and accurate quantity description of risk factors influence the effectiveness of risk assessment of a particular facility. This allows to avoid or decrease problems in various logistical undertakings. The article presents an analysis of risk assessment possibilities for temporary bridges. It was assumed that bridges are very important elements of road infrastructure. Thus, the problem of risk assessment in road transport was directly correlated with a possible bridge infrastructure fault. Moreover, the article presents an original method of analysis of one bridge exploitation risk factor, i.e. the fatigue risk factor. The analysis was conducted on the example of temporary bridges based on one of the selected method of multicriteria optimisation, i.e. the Analytic Hierarchy Process.

Identification of Risk Factors of Development and Operation of Roads in the Light of Surveying Work

Abstract This article aims to identify potential risk factors affecting the implementation and synchronisation of surveying and construction works during building and operation of roads. The task was executed on the basis of literature studies and experience. The article is an introduction to the research that has been conducted by the authors on the reasonably precise index of factors which one may deal with during the implementation of facilities of this type. The raised issue is crucial for financial and time reasons, but what is important in the roads construction - also for social ones, as prolonged traffic disruption adversely affects the environment.

Identification of the risk of disturbances of operation of transport infrastructure in crisis conditions

The paper contains a specification of the notions of risk, transport infrastructure and crisis situation. The study also presents selected methods of identification of risks to transport infrastructure facilities, based on the example of a bridge facility.

Statistical methods for classification of unmanned aerial vehicles

When making decisions regarding multiple objects, researchers often face the problem of choosing the appropriate method for grouping objects with similar characteristics [1]. The present article proposes the use of agglomeration methods to search for links between individual unmanned aerial vehicles (UAVs). An undoubted advantage of the application of agglomeration methods is the possibility of searching for similarities even between many objects to describe which numerous characteristics can be used. The aim of this article is to investigate interrelations between the selected UAVs. For the study purposes the cluster analysis was employed comprising algorithms for grouping objects so that the degree of linkage between elements from the same group was as high as possible, while with elements from the other groups as low as possible. Identification of similar objects, merging them into homogeneous groups, gives the opportunity to organize and classify them.

The influence of gossip and reputation on a business process oriented multi-agent system

The construction of business process oriented agent systems involves the development of mechanisms to support their management and monitoring. One of the theories that can be used to address the task is the concept of gossip focusing on agents’ behaviors in relation to knowledge sharing taking place in a multi-agent system. The autonomy that software agents enjoy in performing their operations means that they are able to propagate false information and hence compromise the system’s health. An indicator that can be deployed to prevent this from happening is an agent’s reputation regarding the gossip that it spreads. Once such an indicator is implemented in an agent system, the reputation of an agent can be used by the system as a factor in making decisions about each agent’s credentials and, consequently, its continued presence in the system. The aim of the paper is to investigate the possibility of employing an indicator of gossip reputation in a software agent society to improve its operation. In its first part, the paper discusses selected elements of the gossip theory, to subsequently determine what knowledge is shared in the system and to propose an indicator for measuring an agent’s reputation. Further, the article provides an account of a relevant scientific experiment and delivers conclusions derived from it.The construction of business process oriented agent systems involves the development of mechanisms to support their management and monitoring. One of the theories that can be used to address the task is the concept of gossip focusing on agents’ behaviors in relation to knowledge sharing taking place in a multi-agent system. The autonomy that software agents enjoy in performing their operations means that they are able to propagate false information and hence compromise the system’s health. An indicator that can be deployed to prevent this from happening is an agent’s reputation regarding the gossip that it spreads. Once such an indicator is implemented in an agent system, the reputation of an agent can be used by the system as a factor in making decisions about each agent’s credentials and, consequently, its continued presence in the system. The aim of the paper is to investigate the possibility of employing an indicator of gossip reputation in a software agent society to improve its operation. In its fir...

Application of portfolio methods for the classification of unmanned aerial vehicles

Portfolio methods provide the identification of the market position of a product offered by a particular enterprise, and thus indicate the organization’s long-term development prospects. In this paper the authors present the possibility of applying portfolio methods for the classification of Unmanned Aerial Vehicles (UAV) used in military engineering. The computations included 15 UAV models available on the Polish market. The analysis made it possible to classify the UAVs in question into one of the four groups, and to choose the optimal UAV model with a view to one of the criteria adopted.