We study the exact and approximate controllabilities of the Langevin equation describing the Brownian motion of particles with a white noise. The Langevin equation is shown to describe also the bacterial run-and-tumble motion. Applying the Green’s function approach to the Green’s function representation of the Langevin equation, we obtain necessary and sufficient conditions for exact controllability in the form of a finite-dimensional problem of moments. For the approximate controllability, we obtain only sufficient conditions. The sets of resolving controls are characterized in both cases. The theoretical derivations are supported by a numerical analysis.

In the paper, the research results on the removal of aliphatic hydrocarbons (C7 to C30) on constructed

wetlands have been presented. The research has been realized on the semi-technical scale constructed wetlands.

planted with reed Phragmites australis. The experimental installation is located on the filling station in Balice and treats the fraction of stormwater from this utility. The concentrations of total aliphatic hydrocarbons

in analyzed stormwater were between 96.02 µg/dm3 and 6177.33 µg/dm3

, and from 47.55 µg/dm3 to 5011.14

µg/dm3

in effluent from the installation. The average total aliphatic hydrocarbons removal effectiveness was

48%, the values ranged from 19% to 81%. Hydrocarbons C14 to C18 were removed with the lowest effectiveness (26%–32%), the lighter hydrocarbons – with higher one (39%–68%), however the highest removal

effectiveness were observed for the hydrocarbons with the highest carbon atoms numbers (from 51% for C20

to 92%–93% for C26–C30).

The telemetry data are essential in evaluating the performance of aircraft and diagnosing its failures. This work combines the oversampling technology with the run-length encoding compression algorithm with an error factor to further enhance the compression performance of telemetry data in a multichannel acquisition system. Compression of telemetry data is carried out with the use of FPGAs. In the experiments there are used pulse signals and vibration signals. The proposed method is compared with two existing methods. The experimental results indicate that the compression ratio, precision, and distortion degree of the telemetry data are improved significantly compared with those obtained by the existing methods. The implementation and measurement of the proposed telemetry data compression method show its effectiveness when used in a high-precision high-capacity multichannel acquisition system.

The implementation of milk-run in Indonesia has been started since 2005. As a developing

country, there is a challenge to operate milk-run smoothly especially in urban area due to

severe traffic congestion and unfavourable road condition in some areas. This research aimed

to analyze the practice of milk-run operation in one of the biggest Japanese automotive

companies in Indonesia. Transportation Value Stream Mapping (TVSM) is applied in order

to perform just-in-time delivery in the supply chain before operating milk-run. It is discussed

that this company still need to continue in improving milk-run operation. The operation

system needs control and integration from manufacturer, supplier and logistics partner.

The advantage of milk-run operation is cost reduction and also support green logistics in

decreasing emission of carbondioxide (CO2) by reducing the number of trucks used.

The objective of the milk-run design problem considered in this paper is to minimize transportation

and inventory costs by manipulating fleet size and the capacity of vehicles and

storage areas. Just as in the case of an inventory routing problem, the goal is to find a periodic

distribution policy with a plan on whom to serve, and how much to deliver by what

fleet of tugger trains travelling regularly on which routes. This problem boils down to determining

the trade-off between fleet size and storage capacity, i.e. the size of replenishment

batches that can minimize fleet size and storage capacity. A solution obtained in the declarative

model of the milk-run system under discussion allows to determine the routes for each

tugger train and the associated delivery times. In this context, the main contribution of

the present study is the identification of the relationship between takt time and the size

of replenishment batches, which allows to determine the delivery time windows for milkrun

delivery and, ultimately, the positioning of trade-off points. The results show that this

relationship is non-linear.

This paper presents the construction of adequate 3-D computer models for simulation research and analysis of dynamic aspects of caliper disc brakes, as well as of drum brakes, actuated by a short stroke electromagnet or a hydraulic thruster, when these brake types are used in the hoisting mechanism of cranes. The adequacy of the 3-D models has been confirmed by comparing their simulation results with results from an experiment and from classic computational models. The classic computational models, related to the study of main dynamic features of friction brakes, are layouts that are based on a number of assumptions, such as that the braking force instantly reaches its steady-state value, the clearance between the friction lining and the disc/drum is neglected, etc. These assumptions lead to a limitation of research options. The proposed 3-D computer models improve the research layouts by eliminating a number of the classic model assumptions. The improvements are related to the determination of the braking time, braking torque, normal force and other dynamic aspects of the brakes by performing simulations that take into account: the braking force as a function of time, the presence of clearance between the friction lining and the disc/drum, etc.

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

The paper presents the algorithms for kinematic analysis, trajectory planning, dynamics of kinematic chain and driving units elaborated for manipulators and robots with kinematic chains of serial structure with revolute pairs with perpendicular or parallel axes. Elastic deflections of driving units as well as action of external forces on end-effector have been taken into account. The simulating software was created using the modular structure of modeling process. The application of software for testing the robots accuracy and running speed acc. to ISO 9283 is also presented.

In 2015 Supreme Audit Office published the report concerned the quality of doctoral studies in Poland. Result of the conducted audit is alarming: “there are serious doubts both about quality and effectiveness of mass doctoral education” (SAO 2015). The text presents an overview of university regulations concerned the evaluation of annual achievements of PhD students (in the area of social sciences) and indicates its potentially negative consequences for the quality of their academic activity. The article refers to two terms – “running for points” and “parametric game”– introduced by Emanuel Kulczycki to describe consequences of economization of research evaluation system, i.e. measuring academic activities and turning them into points-based rewards.

An important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured for fixing the rotor blades. The extreme stresses in this place occur during the start-up and the shaft heating to normal operating temperature. The process needs optimisation. Optimization tasks are multidisciplinary issues and can be carried out using different methods. In recent years, particular attention in optimisation has been paid to the use of artificial intelligence methods. Among them, a special role is assigned to genetic algorithms. The paper presents a genetic algorithm method to optimise the steam turbine shaft heating process during its start-up phase. The presented optimization task of this algorithm is to carry out the process of the shaft heating as soon as possible at the conditions of not exceeding the stresses at critical locations at any heating phase.

Footbridges, like all building structures, must be designed in a way that ensures their safe and comfortable use. Steel footbridges characterised by low vibration damping often turn out to be a structure susceptible to the dynamic influence of users during various forms of their activity. For these structures, the impact of running users may be a key type of dynamic load for the verification of the serviceability limit state due to vibrations. In the literature, there are several proposals for models of dynamic load generated by runners (models of ground reaction forces – GRF). The paper presents the characteristics, analyses and comparisons of selected GRF load models. The analyses were performed using the GRF recorded during the laboratory tests of runners (tests planned and carried out by the author) and the GRF determined using various load models. In order to illustrate the accuracy of the estimation of the dynamic response of the structure, depending on the GRF model used, dynamic field tests and dynamic numerical analyses of the selected steel footbridge were carried out. The obtained results were analysed and compared.

This paper presents details of 37 storm surges that occurred on the Polish southern Baltic Sea coast in the autumn/winter 2021–2022 season. They emerged during the passage of a larger number of low-pressure systems than usual from the SW-W direction over the Baltic Sea. Based on an assessment of meteorological and hydrological conditions during the storms, the relationship between the wind parameters, the sea level increase, and its maximum elevation was ascertained. The relationship between the sea level and the run-up elevation was ascertained. The elevation of the sea level and run-up on the onshore were compared with the beach height. Sections with a lower beach were affected by dune erosion already at a lower sea level. The dependence of dune erosion on the sea level elevation was presented. The value of the dune base retreat depended on the beach elevation and the sea level expressed by the onshore flow called run-up. The most significant erosion occurred during the storm Nadine with a sea level of 1.0–1.28 m AMSL. The average erosion varied between 1.0 and 4.5 m. The maximum erosion values reached 8–13 m.

In this work, we perform an analysis of the characteristics of the one-year and ultimate reserve risk distributions commonly used in actuarial science: duration, first development factor, coefficient of variation, skewness coefficient, skewness-to-CoV ratio, emergence factor, emergence pattern, and risk margin run-off patterns. Our study is based on empirical data for two European markets: the Polish and Slovak markets. We provide benchmarks and ranges for the considered characteristics, as well as analyse the relations between them. We study Solvency II lines of business and compare our coefficients of variation to the Standard Formula reserve risk standard deviations. We investigate more deeply the topic of emergence pattern and risk margin run-off patterns.

To determine the relationships between operating conditions and tribological properties of Zn-30Al-3Cu alloy, its wear characteristics were investigated at wide ranges of oil flow rate, pressure and sliding velocity using a block-on-disk type test apparatus. The results are compared to those of SAE 660 leaded bearing bronze. Wear loss of these materials increased with sliding distance, pressure and sliding velocity, but decreased slightly with oil flow rate. The relationships between operating conditions and lubricated wear properties of Zn-30Al-3Cu alloy were determined by nonlinear regression analysis of the experimental data. Lubricated wear behavior of the zinc-based alloy was discussed in terms its microstructure and mechanical properties, and test conditions.

The Authors present the problems of theoretical analysis and experimental research related to the possibilities of energy recovery in selected phases of operating and running cycles of self-driven crane. Heavy machinery powered by diesel engines is a source of solid toxic emissions. In order to limit these emissions, one install filters and filter regeneration systems. According to the concept presented here, the recovered energy might be utilised for regeneration of these filters by burning off accumulated solid particles (soot). Mechanical energy would be the power source to drive DC generators - the mechanical-into-electric energy converters. Filter's heating resistors, acting as the generators' load, would radiate a power of 3-;-5 MJ to initiate burning of soot in the filter. The calculations of energy consumed during sheave block lowering phase were made for three different lifting capacities taking into account the boom length and crane reach. Three running cycles of the crane: highroad, urban and off-road ones were also analysed. The time functions of variations of crane running speed and power of motion resistance at driving wheels were found. The results provided the background for determination of theoretical values of energy to be regained during braking phase of the analysed cycles. The structure and operation of experimental stands was discussed. The stands contain units that, at proper size factor, represent the processes that occur in real cranes and that are related only to energy recovery. Computer software for system simulation, control and measurement was described. Measurement results and result analysis are presented. The value of energy found theoretically was compared with the energy recovered during experimental tests. The paper also contains simplified kinematic schemes of selected units of crane lifting and driving systems, including an additional DC generator. This concept, however, needs verification in future design solutions.

Recently, simultaneous monitoring of process mean and variability has gained increasing attention. By departing from the accurate measurements assumption, this paper investigates the effect of gauge measurement errors on the performance of the maximum generally weighted moving average (Max-GWMA) chart for simultaneous monitoring of process mean and variability under an additive covariate model. Multiple measurements procedure is employed to compensate for the undesired impact of gauge inaccuracy on detection capability of the Max- GWMA chart. Simulation experiments in terms of average run length (ARL) are conducted to assess the power of the developed chart to detect different out-of-control scenarios. The results confirm that the gauge inaccuracy affects the sensitivity of the Max-GWMA chart. Moreover, the results show that taking multiple measurements per item adequately decreases the adverse effect of measurement errors. Finally, a real-life example is presented to demonstrate how measurement errors increases the false alarm rate of the Max-GWMA chart.

The implementation of construction projects in Warsaw is associated with increasing difficulties in preparation, obtaining the relevant building permits and licences, partly due to the lack of water and sewage infrastructure and the inadequate management of rainwater in the city. All this leads to an increase in the cost of the construction projects undertaken. To illustrate a number of issues related to stormwater management in the city and the resulting problems, the study provides a number of different case studies, stylised facts and abductive conclusions to develop the best explanation for the existing problems. Specifically, the study presents the barriers to stormwater management in the city of Warsaw through an analysis of a hypothetical investment process (related to the Wawer Canal). The case studies analysed concern the deterioration of the “Bernardine Water” reservoir and the lack of appropriate investments in the Sluzewiecki Stream catchment, as well as a number of conflicting conditions in stormwater management in Warsaw. In contrast, examples of successful investments in stormwater management are also shown, e.g. Radex Park Marywilska, Stegny Południe settlement, Fort Bema settlement in Bemowo. In this way it is shown that with the right approach it is possible to carry out construction investments in water and wastewater infrastructure in an appropriate way, thus avoiding many stormwater management problems. The main conclusion of the study is that insufficient consideration of stormwater drainage issues in spatial planning will lead to further flooding and increasing water management problems.

Improving production processes includes not only activities concerning manufacturing itself, but also all the activities that are necessary to achieve the main objectives. One such activity is transport, which, although a source of waste in terms of adding value to the product, is essential to the realization of the production process. Over the years, many methods have been developed to help manage supply and transport in such a way as to reduce it to the necessary minimum. In the paper, the problem of delivering components to a production area using trains and appropriately laid-out carriages was described. It is a milk run stop locations problem (MRSLP), whose proposed solution is based on the use of heuristic algorithms. Intelligent solutions are getting more and more popular in the industry because of the possible advantages they offer, especially those that include the possibility of finding an optimum local solution in a relatively short time and the prevention of human errors. In this paper, the applicability of three algorithms – tabu search, genetic algorithm, and simulated annealing – was explored.