The problem of consolidation of soil has been widely investigated. The basic approach was given by Terzaghi who assumed soil of constant physical and mechanical parameters. In the case of peat consolidation, the permeability coefficient of soil and the elasticity modulus are functions of the settlement which is an important additional factor. The model proposed here assumes varying the elasticity and permeability coefficients. Moreover, the settlement is described by the so-called elementary curve which was approximated empirically based upon laboratory tests. The model allows to consider the case when the filtration in the peat body goes in horizontal direction. It happens so when the charging layer does not receive outgoing water from the pores. The model includes also the case when the load involving consolidation varies in time i.e. the charging layer grows up gradually. The model has been applied practically in several cases and it comes that there is a good agreement between calculated and measured settlement of the consolidated peat layer.
The purpose of the paper is to present the author’s reflections on the origin and popularity of various approaches to maintenance and improvement of production processes, their terminological consistency, understanding, and practical application of their principles. The author’s reflections are based on his observations made over his many years of activity as a lecturer and consultant in the area of production engineering and management. It was shown that there is a need to make scientists and practitioners aware of the relatively large degree of freedom in defining the scope and way of application of strategies of continuous improvement. The author’s proposal is to refer to all approaches to maintenance and improvement of production processes with the title “Strategies of Efficient Action” and all supporting methods as “Practices of Efficient Action”. Considerations presented in the paper can be useful in more and more efficiently applying the power of TQM, Six Sigma, Lean Manufacturing and other strategies of processes maintenance and improvement in the daily activities of companies.
Many business offices around the world are organized as open plan offices. Therefore, studies about the acoustic comfort of the people who work in them have become increasingly important. The focus of this work is the acoustic evaluation of an open plan office combining several architectural characteristics and levels of ambient noise. This evaluation was performed through a computational model calibrated from a real office. The rate of spatial decay of sound pressure levels per distance doubling (DL2) and the speech transmission index (STI) were simulated for the acoustic evaluation of the office, allowing for the determination of the radius of distraction (rD). These parameters were simulated for 6 situations using different floor and ceiling covering materials and inserting or withdrawing screens between workstations. In addition, STI and rD were simulated under two conditions of ambient noise. The results indicated that the DL2 and rD are adequate acoustic parameters for the acoustic evaluation and improvement of an open plan office. The DL2 was strongly influenced by the presence or absence of screens between workstations and by the ceiling covering material. The rD was more sensitive to changes in ambient noise.
Lean has established itself as the primordial approach to obtain operational excellence. Its simple and intuitive techniques focus on reducing lead time through continuous improvement, involving all levels of employees in the organization. However, the rate of successful implementations has remained low. This paper contributes to the understanding of continuous improvement in a Lean context, by analyzing a database of almost 10.000 improvement actions, from 85 companies, covering the time frame 2010–2018. It discusses categories of actions, their impact and cost, as well as key characteristics of the companies. It proposes an objective criterion to identify “success” and “failure” in Lean implementation and tries to link these to operational results. It is probably the ﬁrst time an analysis of this magnitude on the subject has been performed.
In a reality of global competition, companies have to minimize production costs and increase productivity in order to boost com-petitiveness. Facility layout design is one of the most important and frequently used efficiency improvement methods for reducing operational costs in a significant manner. Facility layout design deals with optimum location of facilities (workstation, machine, etc.) on the shop floor and optimum material flow between these objects. In this article, the objectives and procedure of layout design along with the calculation method for layout optimization are all introduced. The study is practice-oriented because the described case study shows how the layout of an assembly plant can be modified to form an ideal re-layout. The research is novel and innovative because the facility layout design and 4 lean methods (takt-time design, line balance, cellular design and one-piece flow) are all combined in order to improve efficiency more significantly, reduce costs and improve more key performance indicators. From the case study it can be concluded that the layout redesign and lean methods resulted in significant reduction of the following seven indicators: amount of total workflow, material handling cost, total travel distance of goods, space used for assembly, number of workers, labor cost of workers and the number of Kanban stops.
The material presents a real problem inherent in the management of computer systems, namely that of finding the appropriate system settings and thus being able to achieve the expected perfor- mance. The material also presents a prototype which aims to adapt the system in such a way as to achieve the objective, defined as the application efficiency. The prototype uses a resource-oriented mechanism that is built into the OS Workload Manager and is focused on a proposed goal-oriented subsystem based on fuzzy logic, managing resources to make the best use of them, and pursuing translation to the use of system resources, including nondeterministic technology-related factors such as duration of allocation and release of the resources, sharing the resources with the uncapped mode, and the errors of performance measurement.
Six Sigma as the continuation of comprehensive quality management TQM is of interest to many enterprises. Unfortunately, not everybody successfully implements quality improvement projects using Six Sigma tools. This approach requires proper preparation in many areas of the company’s operation, including: organization of processes, establishing measures, employee engagement and creating conditions for continuous improvement. The goal of the article is to present on the case study the idea of using the organizational maturity model for production management to assess a readiness of organization to implement Six Sigma. The case study presents a company maturity level diagnosis and a successful project of quality and productivity improvement using the Six Sigma concept, confirming that the organization’s maturity model is the appropriate tool for assessing multi-faceted preparation for successful implementation of Six Sigma projects.
The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the entire manufacture of the casts. The current state of the production process as well as the organization of the work and production technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.
Scientists around the world agree that nowadays, science is facing severe challenges like poor peer-review system, replicability crisis, or locked science behind paywalls. The National Science Center addresses at least some of them by introducing procedures that promote integrity, ethics, social responsibility, transparency, and openness in science.
There is a general agreement that remembering depends not only on the memory processes as such but rather that encoding, storage and retrieval are under the constant influence of the overarching, metacognitive processes. Moreover, many interventions designed to improve memory refer in fact to metacognition. Most attempts to integrate the very different theoretical and experimental approaches in this domain focus on encoding, whereas there is relatively little integration of approaches that focus on retrieval. Therefore, we reviewed the studies that used new ideas to improve memory retrieval due to a “metacognitive intervention”. We concluded that whereas single experimental manipulations were not likely to increase metacognitive ability, more extensive interventions were. We proposed possible theoretical perspectives, namely the Source Monitoring Framework, as a means to integrate the two, so far separate, ways of thinking about the role of metacognition in retrieval: the model of strategic regulation of memory, and the research on appraisals in autobiographical memory. We identified venues for future research which could address, among other issues, integration of these perspectives.
A transformer is an important part of power transmission and transformation equipment. Once a fault occurs, it may cause a large-scale power outage. The safety of the transformer is related to the safe and stable operation of the power system. Aiming at the problem that the diagnosis result of transformer fault diagnosis method is not ideal and the model is unstable, a transformer fault diagnosis model based on improved particle swarm optimization online sequence extreme learning machine (IPSO-OS-ELM) algorithm is proposed. The improved particle swarmoptimization algorithm is applied to the transformer fault diagnosis model based on the OS-ELM, and the problems of randomly selecting parameters in the hidden layer of the OS-ELM and its network output not stable enough, are solved by optimization. Finally, the effectiveness of the improved fault diagnosis model in improving the accuracy is verified by simulation experiments.
The article presents an analysis of the multi-operation hot die forging process, performed on a press, of producing a lever forging used in the motorcycles of a renowned producer by means of numerical simulations. The investigations were carried out in order to improve (perfect) the currently applied production technology, mainly due to the presence of forging defects during the industrial production process. The defects result mainly from the complicated shape of the forging (bent main axis, deep and thin protrusions, high surface diversity in the cross section along the length of the detail), which, during the filling of the die by the deformed material, causes the presence of laps, wraps and underfills on the forging. Through the determination of the key parameters/quantities during the forging process, which are difficult to establish directly during the industrial process or experimentally, a detailed and complex analysis was performed with the use of FEM as well as through microstructure examinations. The results of the performed numerical modelling made it possible to determine: the manner of the material flow and the correctness of the impression filling, as well as the distributions of temperature fields and plastic deformations in the forging, and also to detect the forging defects often observed in the industrial process. On this basis, changes into the process were introduced, making it possible to improve the currently realized technology and obtain forgings of the proper quality as well as shape and dimensions.
Coordinate Measurement Machines (CMMs) have been extensively used in inspecting mechanical parts with higher accuracy. In order to enhance the efficiency and precision of the measurement of aviation engine blades, a sampling method of profile measurement of aviation engine blade based on the firefly algorithm is researched. Then, by comparing with the equal arc-length sampling algorithm (EAS) and the equi-parametric sampling algorithm (EPS) in one simulation, the proposed sampling algorithm shows its better sampling quality than the other two algorithms. Finally, the effectiveness of the algorithm is verified by an experimental example of blade profile. Both simulated and experimental results show that the method proposed in this paper can ensure the measurement accuracy by measuring a smaller number of points.
Lean manufacturing [LM], quality management system and environmental management system are clear initiatives with a goal of improving effectiveness and efficiencies of organizations. Many organisations tackle lean philosophy, ISO standards individually but this kind of attempt do not focus on the synergy and the advantage from the potential collaboration. This paper aims to present the possibility of integration Lean Management concept with ISO management systems – Quality Management System [QMS] ISO 9001and Environmental Management System [EMS] ISO 14001 already implemented in the enterprises. The integration of these three concepts can be obtain due to improvement of main KPI’s defined in the organization. Based on critical research literature and participant observation presented as a case study (one of the author of the paper works as a consultant and is being implemented Lean Manufacturing concept in different organization since ten years) authors defined concept of integration of EMS and QMS (already implemented in the organization) with chosen Lean Management tools. Concept has been developed based on literature analysis and experience of the authors. Results and summary from concept implementation has been described in last chapter of the paper.
The main purpose of this article is to present an author’s methodology of production levelling and to show the impact of levelling on the time during which the product passes through the process and on staff performance. The article presents the analysis of literature concerning the method of improving the production process, especially taking production levelling into consideration. The authors focussed on the definition and methodologies of production levelling. A diagram of interrelations showing determinants and efficiency measures of production levelling as well as an author’s production levelling methodology have been presented. An example of the implementation of production levelling in one of the departments of a company manufacturing surgical instruments has also been shown. Analysis of the current state, stages of implementation and end effects have been presented. Attention was focussed on the time during which the product passes through the process and on staff performance.
The radial distribution system is a rugged system, it is also the most commonly used system, which suffers by loss and low voltage at the end bus. This loss can be reduced by the use of a capacitor in the system, which injects reactive current and also improves the voltage magnitude in the buses. The real power loss in the distribution line is the I2R loss which depends on the current and resistance. The connection of the capacitor in the bus reduces the reactive current and losses. The loss reduction is equal to the increase in generation, necessary for the electric power provided by firms. For consumers, the quality of power supply depends on the voltage magnitude level, which is also considered and hence the objective of the problem becomes the multi objective of loss minimization and the minimization of voltage deviation. In this paper, the optimal location and size of the capacitor is found using a new computational intelligent algorithm called Flower Pollination Algorithm (FPA). To calculate the power flow and losses in the system, novel data structure load flow is introduced. In this, each bus is considered as a node with bus associated data. Links between the nodes are distribution lines and their own resistance and reactance. To validate the developed FPA solutions standard test cases, IEEE 33 and IEEE 69 radial distribution systems are considered.
Accurate network fault diagnosis in smart substations is key to strengthening grid security. To solve fault classification problems and enhance classification accuracy, we propose a hybrid optimization algorithm consisting of three parts: anti-noise processing (ANP), an improved separation interval method (ISIM), and a genetic algorithm-particle swarm optimization (GA-PSO) method. ANP cleans out the outliers and noise in the dataset. ISIM uses a support vector machine (SVM) architecture to optimize SVM kernel parameters. Finally, we propose the GA-PSO algorithm, which combines the advantages of both genetic and particle swarm optimization algorithms to optimize the penalty parameter. The experimental results show that our proposed hybrid optimization algorithm enhances the classification accuracy of smart substation network faults and shows stronger performance compared with existing methods.