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Search results for: LEAD TOXICITY
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Potential applicability of ontologies for the evaluation of information technology
PublicationIn this article we present the possibilities of using ontologies as a part of a multi-agent system (MAS) designed for the evaluation of information technologies. This is a part of a broader idea devel-oped by the team of researchers at Gdańsk University of Technology. The article deals with defining ontologies, presenting main technologies for their design and implementation and proposes, initially, domains of the ontologies' interest...
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THE INFLUENCE OF POLYMER STRIPS IN REDUCTION OF A STEEL GRANDSTAND VIBRATIONS
PublicationGrandstands are types of structures commonly used during sport events or music concerts. Dynamic loads generated by crowd movement may have significant influence on human perception as well as may lead to the destruction of a structure. Lighter and more slender structural steel members are more easily excitable by spectators. If the synchronized movement is tuned with the natural frequency of the affected part of the structure,...
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ENERGY STORAGE IN COMPRESSED AIR – SOLUTION SUPPORTING RENEWABLE ENERGY SOURCES
PublicationThis article presents a brief description of a power system, the current national power system daily load, the use of wind power as a renewable energy source and its share in the national load. It also discusses the methods for storing energy, their characteristics and possible solutions. The power storage and generation solution proposed in the article is based on the collaboration between a gas turbine and an air storage system....
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Discrete random variables in reliability calculations of a reticulated shell
PublicationImplementation of the Point Estimation Method (PEM) in the reliability analysis of a three-dimensional truss structure is presented in the paper. The influence of geometric and material random parameters on the truss load-carrying capacity was investigated. The analysis was performed for different combinations of basic variables. Symmetric and asymmetric cases of snow load were taken to assess the structural reliability. Sensitivity...
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OPTICAL STRAIN MEASUREMENT OF CONCRETE VERSUS MANUAL EXTENSOMETER MEASUREMENT BASED ON THE TEST RC DEEP BEAM IN A COMPLEX STATE OF STRESS
PublicationThe purpose of this study is to compare the strain measurement techniques of concrete in R-C element subjected to the monotonic load up to the failure. In the analysis manual extensometer methods of measurements and the optical system ARAMIS for non-contact three-dimensional measurements of deformation was used. The test sample was a cantilever deep beam loaded throughout the depth which was a part of the reinforced concrete deep...
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Displacement piles - classification and methods for the calculation of bearing capacity.
PublicationDisplacement piles belong to a group of technologies whose main idea is to install or make a pile without extracting ground material. According to definition, contained in PN-EN:1997-1:2008, displacement piles should be considered as driven, pressed in using vibrators and made with the use of spread augers. The classification of piles used so far with regard to the technology of execution is modified. An additional element is the...
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Justifying the prolongation of the service life of the bearing structure of a tank car when using Y25 bogies
PublicationThis paper substantiates the use of Y25 bogies under tank cars in order to prolong their service life. The reported study has been carried out for a tank car with rated parameters, as well as the actual ones, registered during full-scale research. Mathematical modeling was performed to determine the basic indicators of the tank car dynamics. The differential equations of motion were solved by a Runge-Kutta method using the Mathcad...
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Broadband Modeling of Motor Cable Impact on Common Mode Currents in VFD
PublicationExamination of conducted EMI generation and propagation in AC motor drives fed by frequency converter requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. AC motor winding voltage transients and related common mode currents are significantly correlated with resonance effects occurring in converter's load circuits. Intensity levels of these phenomena depend...
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Core loss resistance impact on sensorless speed control of an induction motor using hybrid adaptive sliding mode observer
PublicationInduction motors (IMs) experience power losses when a portion of the input power is converted to heat instead of driving the load. The combined effect of copper losses, core losses, and mechanical losses results in IM power losses. Unfortunately, the core losses in the motor, which have a considerable impact on its energy efficiency, are not taken into account by the generally employed dynamic model in the majority of the studies. Due...
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Lateral forces determine dimensional accuracy of the narrow‑kerf sawing of wood
PublicationThe shrinking global forest area limits the supply of industrially usable raw resources. This, in combination with the ever‑increasing consumption of timber due to population growth can lead to the lack of a positive balance between the annual volumetric growth and consumption of wood. An important innovation toward increasing environmental and economic sustainability of timber production is to reduce the volume of wood residues...
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Influence of the grains shape on the mechanical behavior of granular materials
PublicationDiscrete Element Method is a numerical method suitable for modeling geotechnical problems concerning granular media. In most cases simple forms of grains, like discs or spheres, are used. But these shapes are capable of soil behavior modeling up to a certain point only, they cannot reflect all of the features of the medium (large shear resistance and large volumetric change). In order to reflect the complex behavior of the real...
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Modeling of Surface Roughness in Honing Processes by UsingFuzzy Artificial Neural Networks
PublicationHoning processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present study, fuzzy artificial neural networks are employed for modeling surface roughness parameters obtained in finishing honing operations. As...
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Cable-stayed cantilever structures as an expat of unique application in the construction of a building located in seismic area – an author’s project of multifunctional building in Lisbon, Portugal
PublicationThe article presents numerical simulations for the modelling of seismic impact on the structure of unique cantilever cablestayed structure with application of two methods. The Response Spectrum method, in which a spectrum of the structure's responses to an earthquake's impact is generated and the Accelerogram method, in which we generate dynamic load in the form of a diagram of the connection between acceleration and time for...
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Influence of Fluid Compressibility and Movements of the Swash Plate Axis of Rotation on the Volumetric Efficiency of Axial Piston Pumps
PublicationThis paper describes the design of a swash plate axial piston pump and the theoretical models describing the bulk modulus of aerated and non-aerated fluids. The dead space volume is defined and the influence of this volume and the fluid compressibility on the volumetric efficiency of the pump is considered. A displacement of the swash plate rotation axis is proposed to reduce the dead space volume for small swash plate swing angles....
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Aspect-Oriented Management of Service Requests for Assurance of High Performance and Dependability
PublicationA new approach to service requests management in case of insufficient hardware resources is proposed. It is based on wide aspects of requests analysis and it assures reliable and fast access to priority services. Requests are analyzed for, among others, time of occurrence, category of user who made the request, type of service, current system load and hardware utilization. Deterministic but dynamic rules help to manage system load...
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Occurrence of Surface Active Agents in the Environment
PublicationDue to the specific structure of surfactants molecules they are applied in different areas of human activity (industry, household). After using and discharging from wastewater treatment plants as effluent stream, surface active agents (SAAs) are emitted to various elements of the environment (atmosphere, waters, and solid phases), where they can undergo numerous physic-chemical processes (e.g., sorption, degradation) and freely...
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Analytical procedures for the determination of surfactants in environmental samples
PublicationBecause of their specific physical and chemical properties (amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate.In the...
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Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities
PublicationAll activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause...
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Insights into modification of lignocellulosic fillers with isophorone diisocyanate: structure, thermal stability and volatile organic compounds emission assessment
PublicationThis study presents an analysis of the structure and properties of different types of lignocellulosic fillers modified by isophorone diisocyanate (IPDI) to provide insights into the possibility of their application to the manufacturing of wood polymer composites (WPCs). Moreover, it deals with the environmental aspects of modified fillers, by assessment of volatile organic compounds (VOCs) emitted during modification, as well as...
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Assessment and design of greener deep eutectic solvents – A multicriteria decision analysis
PublicationDeep eutectic solvents (DES) are often considered as green solvents because of their properties, such as negligible vapor pressure, biodegradability, low toxicity or natural origin of their components. Due to the fact that DES are cheaper than ionic liquids, they have gained many applications in a short period of time. However, claims about their greenness sometimes seem to be exaggerated. Especially, bearing in mind lots of data...
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Aggregation properties of some zirconium phosphate loaded with dirhenium(III) complexes
PublicationOne of the important areas of modern science is the selection of the right forms of drug delivery. Layered inorganic nanoparticles, such as zirconium phosphate, have proven themselves well in this area. The study of the properties of these systems and methods of their preparation makes it possible to determine a rational technology of their manufacture, storage conditions as well as suggest a possible mechanism of therapeutic action....
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Multi Parameter Sliding Test Result Evaluation for The Selection of Material Pair for Wear Resistant Components of a Hydraulic motor Dedicated for Use With Environmentally Friendly Working Fluids
PublicationIn the paper the method and results are presented of the testing of tribological performance of a number of hard materials available commercially. The tests consisted in unidirectional sliding with liquid lubrication. The load and velocity regime chosen were similar to a standard four-ball lubricity test with constant velocity and load increasing over time. The regime was modified in such a way that over the initial part of the...
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Application of subsurface vertical flow constructed wetlands to reject water treatment in dairy wastewater treatment plant
PublicationThe paper presents the effects of applying subsurface vertical flow constructed wetlands (SS VF) for the treatment of reject water generated in the process of aerobic sewage sludge stabilization in the biggest dairy wastewater treatment plant (WWTP) in Poland. Two SS VF beds were built: bed (A) with 0.65 m depth and bed (B) with 1.0 m depth, planted with reeds. Beds were fed with reject water with hydraulic load of 0.1 m d-1 in...
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Experimental and Numerical Study on Dynamics of Two Footbridges with Different Shapes of Girders
PublicationThe paper presents the experimental and numerical results of the dynamic system identification and verification of the behavior of two footbridges in Poland. The experimental part of the study involved vibration testing under different scenarios of human-induced load, impulse load, and excitations induced by vibration exciter. Based on the results obtained, the identification of dynamic parameters of the footbridges was performed...
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Multimedia polysensory integration training system dedicated to children with educational difficulties
PublicationThis paper aims at presenting a multimedia system providing polysensory train- ing for pupils with educational difficulties. The particularly interesting aspect of the system lies in the sonic interaction with image projection in which sounds generated lead to stim- ulation of a particular part of the human brain. The system architecture, video processing methods, therapeutic exercises and guidelines for children’s interaction...
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Problems of collisions between adjacent steel structures under earthquake excitation
PublicationNowadays, the high level of urbanization forces the designers to design closely-separated structures and to take into account many factors influencing the response of these structures, which may collide due to insufficient separation distance during moderate to strong ground motions. Recent observations as well as numerical and experimental investigations have confirmed that the interactions between structures may lead to significant...
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Adam Smith - pięć razy o racjonalności w ekonomii (Z okazji 240 rocznicy ukazania się "Bogactwa Narodów").
PublicationNiniejszy tekst jest syntetyczną próbą, próbą wykraczającą poza ramy samej ekonomii i wkraczającą w pole filozofii, socjologii i antropologii, umiejscowienia myśli Adama Smitha w szerszej perspektywie, perspektywie mechanizmów kształtowania się w nowożytności nowego rodzaju społeczeństwa i związanych z tym zmian mentalnych mających odbicie w myśli europejskiej. Ogrom problematyki zawęża temat do fundamentalnego dla ekonomii jako...
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Sensorless Disturbance Detection for Five Phase Induction Motor with Third Harmonic Injection
PublicationThe paper presents a sensorless disturbance detection procedure that was done on a five phase induction motor with third harmonic injection. A test bench was developed where a three phase machine serves as disturbance generator of different frequencies. The control of the machines is based on multi scalar variables that ensures an independent control of the motor EMF and the rotor flux. For disturbance identification a speed observer...
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An Extended Control of the Input Angle for Matrix Converters Connected with the Non-Unity Power Factor Loads.
PublicationThis paper proposes a novel PWM modulation algorithm for Multiphase Conventional Matrix Converters (MCMC), with 3 inputs and k outputs, using the transfer function of the load angle. The proposed approach extends the range of power angle control at the input during the operation with a maximum voltage transfer ratio. The proposed concept is based on the Direct Analytic Voltage PWM (DAV--PWM) modulation with an elliptical trajectory...
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Baltic Sea climate fever. Creative solutions for waterfront cities in the context of climate change
PublicationThe goal of the research is to recognize climate change impact on Baltic Sea cities and description of strengths and weaknesses of cities strategies and activities. The range of research has been limited to 3 cities in the Baltic Sea (Copenhagen, Gothenburg, Tallinn) and Tricity as an area for which recommendations will be proposed actions in the field of adaptation to climate change. Recommendations for Tricity as a unique group...
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Centrally Pivoted Tilting Pad Thrust Bearing with Carbon-Based Coated Collar—Experimental Results of Low- and Medium-Speed Operation
PublicationExperimental results of the research on a tilting pad thrust bearing with symmetrical pad support in the conditions of high loads and low speeds are presented in the paper. As described in the literature review, experimental results of tilting pad bearings at low speed/high load regime and transient conditions are rare. Unusual material selection - steel pad against a DLC-type coating on the collar was utilized. Such material combination...
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Towards an Understanding of the Stability Assessment of Floating Buildings
PublicationOne of the most important aspects of the design of floating facilities such as ships, floating offshore structures or floating houses is stability. Its impact on both general safety and operational aspects renders it a fundamental consideration already in preliminary design stages. Usually, the concept of sufficient stability of floating buildings is associated with the ability to keep an allowed heel angle and residual freeboard,...
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Experimental test results of an automatic voltage regulator with independent phase voltage controllers
PublicationThe growing number of distributed renewable energy sources and dynamic constant-power loads (e.g. electric vehicle charging stations) pose new challenges for network operators. These changes result in alterations to network load profiles and load flows, leading to greater voltage volatility. One effective solution to these problems can be the use of automatic voltage regulators (AVRs), which stabilize and symmetrize voltage output,...
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Facial data registration facility for biometric protection of electronic documents
PublicationIn modern world, information is crucial, and its leakage may lead to serious losses. Documents as the main medium of information must be therefore highly protected. Nowadays, the most common way of protecting data is using passwords, however it seems inconvenient to type complex passwords, when it is needed many times a day. For that reason a significant research has been conducted on biometric authentication...
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Wpływ procesu redukcji na właściwości strukturalne i mechaniczne szkieł tlenkowych z grupy (Pb,Bi)-(Si,Ge)-O = Influence of reduction process on the structural and mechanical properties of (Pb,Bi)-(Si,Ge)-O oxide glasses
PublicationThe effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some...
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Platform Supporting the Esophageal Impedance Analysis
PublicationThe esophageal pH-impedance examination is one of the most popular diagnostic methods for identifying the upper gastrointestinal tract’s diseases. Inconclusive test evaluation criteria makes it difficult to state the definite diagnosis. In this paper, the computer platform supporting the research and teaching process in the area of pH-impedance analysis is presented. Users, having a variety of mathematical and statistical methods...
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EHV transmission lines wires location on line operation issues - case studies
PublicationTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
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On Applications of Fractional Derivatives in Electromagnetic Theory
PublicationIn this paper, concepts of fractional-order (FO) derivatives are analysed from the point of view of applications in the electromagnetic theory. The mathematical problems related to the FO generalization of Maxwell's equations are investigated. The most popular formulations of the fractional derivatives, i.e., Riemann-Liouville, Caputo, Grünwald-Letnikov and Marchaud definitions, are considered. Properties of these derivatives are...
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Influence of reduction process on the structural and mechanical properties of (Pb,Bi)-(Si,Ge)-O oxide glasses
PublicationThe effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some...
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The application of neural networks in forecasting the influence of traffic-induced vibrations on residential buildings
PublicationTraffic-induced vibrations may cause the cracking of plaster, damage to structural elements and, in extreme cases, may even lead to the structural collapse of residential buildings. The aim of this article is to analyse the effectiveness of a method of forecasting the impact of vibrations on residential buildings using the concept of artificial intelligence. The article presents several alternative forecasting systems for which...
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Geo-engineering computer simulation seems attractive but is it the real world?
PublicationCorrect formulation of the differential equation system for equilibriom conditions of subsoil, especially in terms of controlled numerical calculation, is discussed. The problem of solution stability is also considered. The solution of problems, which are ill-posed, have no practical value in the majority of cases and is this way the engineering prognosis can lead to real disaster. The object of this paper is quite relevant if...
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Proposed concept for the development of residential floating facilities
PublicationCurrently, a dynamic growth of interest in residential buildings located on the water can be observed in Poland. However, the lack of legal regulations, the increase in society's affluence and overpopulation in city centers lead to reflection on the development strategy that should be implemented for maritime construction. The publication presents a proposal of four development strategy concepts: aggressive,...
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Bearing capacity of the working platform with kinematic method
PublicationBearing capacity of the working platform for heavy tracks was analysed using Distinct Layout Optimization (DLO) method. The platform layer constructed from cohesionless soils is resting on weak cohesive subgrade. Different thickness of the platform, its effective angle of internal friction and undrained shear strength of the soft soil were taken into consideration. Kinematic method permits different failure mechanisms to be analyzed....
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Acoustic journal bearing - A search for adequate configuration
PublicationClassical non-contact bearings are already used in a number of specialist applications but there are somespecialist areas where they cannot be used for variety of reasons and acoustic sliding bearings could be an alternative. The paper presents the quest for a configuration of an acoustic journal bearing and shows that the overall shape of the bearing and its geometry are of a vital importance for the load capacity oft he bearing....
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Ancillary services to grids provided with distributed generation
PublicationThe paper introduces system for utilization of the customer-side generated energy. Additionally system can secure some ancillary services to grids. Those services include: current active filtering, load voltage stabilization and in case of grid voltage faults - uninterruptible load supplying (possible with energy storage device). Presented experimental results confirm flexibility of this arrangement in processes of power delivery...
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Mathematical Models in Design Process of Ship Bow Thrusters
PublicationThe paper describes an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an expert...
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Mathematical Models in Design Process of Ship Bow Thrusters
PublicationThe presentation is about an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an...
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TS-based RSM-aided design of cold-formed steel stiffened C-sectional columns susceptible to buckling
PublicationThe paper focuses on joint-performance analysis of a built-up cold-formed thin-walled C-sectional column with a fillister (stiffener) of the same type, interconnected with a series of bolts located along the length of the compressed members in specific spacing. The quantity of bolts and the non-connected starting distance of the fillister are considered random variables of the problem. Optimal distribution of joints on the stiffener...
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Employee Suggestion Program as a way to involve employees in improving business processes
PublicationThe following article presents one of the Lean Management tools – employee suggestion program. Companies consider this method as a way to involve employees in improving business processes. In the first part of the article the author explained the idea of the Japanese management system. The next part presents the philosophy of Kaizen, which is crucial for proper implementation of Lean Management concept in the company. Moreover,...