Since G.E.P. Box introduced central composite designs in early fifties of 20th century, the classic design of experiments (DoE) utilizes response surface models (RSM), however usually limited to the simple form of low-degree polynomials. In the case of small size datasets, the conformity with the normal distribution has very weak reliability and it leads to very uncertain assessment of a parameter statistical significance. The bootstrap approach appears to be better solution than - theoretically proved but only asymptotically equal - t distribution based evaluation. The authors presents the comparison of the RSM model evaluated by a classic method and bootstrap approach.
The subject of outsourcing of personnel services are functions and auxiliary tasks in the operation of a given enterprise. It is based on outsourcing specific tasks and entire personnel processes, as well as hiring employees who carry out tasks entrusted by a client. The main problem faced by enterprises is employee turnover caused by numerous absences, sick leave and holidays, and, as a consequence, employees have more and more delays and do not keep their deadlines. Consequently, they are frustrated that they have to perform more duties from other positions and listen to complaints about continuous decline in work efficiency. The problem of employee turnover is becoming a common phenomenon. Therefore, each company should analyse this problem. Starting from identifying the problem and, as a result, implementing appropriate measures to prevent excessive fluctuation of employees. It is also important to enable employees to develop and organize appropriate working conditions, which will ensure the comfort of work and attachment to the employer.
The development of the common mushroom production sector in Poland and worldwide is accompanied by growing problems of mushroom producers. Production intensification, a constant increase of market expectations, and changing legal regulations, as well as consumers, lead to the situation that producers of common mushrooms have increasing problems associated with the cultivation technology. This situation, therefore, forces producers to look for new solutions. One of such solutions is integrated cultivation of the common mushroom with microbiological preparations. The effect of these preparations on mushroom yielding was investigated in this study.
The article presents the results of the use of SPC tools, i.e. control charts and indicators of the qualitative capability to assess the stability and capability of the production process of rolled products - I-sections. Statistical analysis of the collected data regarding the selected feature of the analysed product - the width of the foot, and the normality of the distribution were done, which showed that the obtained distribution of measurement results is not a normal distribution. As a result, appropriate SPC procedures for non-normal distribution were used. The Pareto-Lorenzo diagram and FMEA method were also used to obtain information about the structure of non-conformities of the analysed product and the level of risk associated with them. This information was used to propose corrective actions and improve the production process of rolled products.
Due to low effectiveness or high costs of using chemical agents in the protection of common mushrooms, producers are forced to look for alternative methods of protection. One such method is the use of preparations containing beneficial microorganisms. A statistical evaluation of this mushroom protection method and determination of the number of infected fruiting bodies is presented in this paper
The Small and Medium Enterprises (SMEs) are the backbone of all the major economies around the world. Majority of these industries are facing tough environment for existence. The present study explored the most common and easily implementable Lean Tools/Techniques amongst the SMEs. This has been achieved via a detailed survey of SMEs in India. Study concludes with nine most common Lean Tools/Techniques implemented across the surveyed population of Indian SMEs.
Petr Savinykh, Vladimir Kazakov, Nikolaj Czerniatiev, Svietlana Gerasimova, Wacław Romaniuk and Kinga Borek
Analysis of patent solutions and research of scientific-research literature in the field of grain processing with technical devices, e.g. kneaders in relation to the quality and digestibility in feed doses of the obtained syrup for the development of beef and dairy cattle was performed. Assumptions of the development trend of feed production, new technologies based on grain, which allow improvement of the quality of feed and reliability of technological lines of animal nutrition, reduce energy consumption, reduce losses were presented. In this regard, reduction of the cost of producing feed compared for example to the production of fodder beet or sugar beet from 1.5 to 2 times is possible.
The paper presents results of analysis of turbidity changes in washing solutions and the quantity of solid particles present in them during regeneration under various temperature conditions. Three solutions taken from breweries after the process of washing brewhouse equipment in the CIP system were evaluated. The results were subjected to statistical analysis, to define the functions that characterize the changes of the tested parameters in relation to time and temperature. The results showed that the tested solutions have different favourable conditions for their regeneration. It has also been shown that the character of changes in solutions in the regeneration process is more advantageously determined on the basis of turbidity tests of solutions.
Krzysztof Jarosz, Piotr Niesłony and Piotr Löschner
In this article, a novel approach to computer optimization of CNC toolpaths by adjustment of cutting speed vcand depth of cut apis presented. Available software works by the principle of adjusting feed rate on the basis of calculations and numerical simulation of the machining process. The authors wish to expand upon this approach by proposing toolpath optimization by altering two other basic process parameters. Intricacies and problems related totheadjustment of apand vcwere explained in the introductory part. Simulation of different variant of the same turning process with different parameter values were conducted to evaluate the effect of changes in depth of cut and cutting speed on process performance. Obtained results were investigated on the account of cutting force and tool life. The authors have found that depth of cut substantially affects cutting force, while the effect of cutting speed on it is minimal. An increase in both depth of cut and cutting speed affects tool life negatively, although the impact of cutting speed is much more severe. An increase in depth of cut allows for a more significant reduction of machining time, while affecting tool life less negatively. On the other hand, the adjustment of cutting speed helpsto reduce machining time without increasing cutting force component values and spindle load.
The paper presents analysis of efficiency of the logging unit comprising Belarus 820 farm tractor and PD80 logging trailer equipped with Ryś-1 crane. Analysis was made based on the working day timing. The unit logged 1- meter long tree pieces (hornbeam, oak, birch) from the area where material for logging was distributed irregularly on the entire felling site. Unfavourable atmospheric conditions were reported during the working day (a thick layer of snow, low temperature, not frozen soil) which could have influenced the unit operation performance. Despite that the performance of the logging unit was comparable to similar logging units described in the literature. Determined coefficient of use of the operating time of the machine K02 was 0.93, coefficient of use of the shift working time K04 − 0.9, coefficient of use of the shift exploitation time K07 − 0.8. Hourly performance in the shift exploitation time was 4.98 m3·h−1, efficiency in the shift working time W02 − 4.80 m3·h−1 and performance in the general shift time W07 − 4.30 m3·h−1.