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  • Author: Katarzyna Kaźmierczak x
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Abstract

The implementation of a new product in serial production is a very important element in the company’s functioning. Manufacturers of cars and complex subassemblies have been working for years according to the established standards of designing and implementing new products for serial production. A great emphasis is placed here on the formal side. In addition, the supplier must prove that has sufficient resources to achieve these objectives. And this is what customers verify during system, product, process and potential audits. However, despite formal approval of parts from the supplier, as well as confirmation of design and production capabilities, defective parts or components are sometimes assembled in cars and distributed to the market. Why does this happen? The answer can often be found not in the forms, manuals or procedures, but in the way the project teams communicate and cooperate with each other and with other organizations. This is confirmed by the research results presented in this paper, which show that one of the key issues requiring improvement during production implementations is not the knowledge of specialists, problems with the machine park or plant equipment, but increasing the ability of specialists and managers to effectively communicate and cooperate. It shows how important is the problem of risk assessment related to the project team for the project within the quality planning. According to the authors, the new model of project plan should be enriched with the risk assessment related to communication in the project team, as a part of the feasibility assessment of the whole project.

Abstract

Today’s world is facing the necessity of reducing air pollution. One of the alternatives is to limit pollution related to road transport by using CNG fuel.

The European Union is imposing increasingly strict requirements regarding the cleanness of car fumes, and the Polish government is endeavouring to take actions aimed at reducing the pollution related to car use by planning the development of transport electromobility. In this article, the authors want to draw attention to methane as an alternative to traditional fuels.

The article presents the results of a survey conducted among drivers, which regarded their readiness to use CNG-powered cars. The results indicate that while respondents appreciate the ecological value of this fuel, they are also worried about safety, which is contradicted by the analysis of CNG advantages and disadvantages.

Abstract

The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft’s class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMśw) and fresh coniferous (Bśw) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for each tree using Kraft’s criteria. The following characteristic were also measured: dbh of the trunk in two directions (N-S and W-E), and crown projection area on the basis of the characteristic tree crown points, projected using of a crown projector, characteristic points in tree crowns (7 to 14 on average). The actual height was determined after trees were felled. The following measurements of the single tree growing space were selected and determined: crown projection area - pk (m2), crown diameter - dk (m), Seebach’s growth space number - dk / d1.3, crown projection area to basal area ratio d 2 k / d 2 1.3, crown deflection coefficient dk / h, single tree space ppd = pk·h (m3). We assessed the strength of the relationships between tree growth parameters and tree growth space, crown length, relative crown length and slenderness. Both the age and dominance position of trees within the stand affected the growth increments. The strongest correlation among measured traits was between the 5-year volume increment and decreasing slenderness.

Abstract

The paper presents an attempt to apply measurable traits of a tree – crown projection area, crown length, diameter at breast height and tree height for classification of 135-year-old oak (Quercus L.) trees into Kraft classes. Statistical multivariate analysis was applied to reach the aim. Empirical material was collected on sample plot area of 0.75 ha, located in 135-year-old oak stand. Analysis of dimensional traits of oaks from 135-year-old stand allows quite certain classification of trees into three groups: pre-dominant, dominant and co-dominant and dominated ones. This seems to be quite promising, providing a tool for the approximation of the biosocial position of tree with no need for assessment in forest. Applied analyses do not allow distinguishing trees belonging to II and III Kraft classes. Unless the eye-estimation-based classification is completed, principal component analysis (PCA) method provided simple, provisional solution for grouping trees from 135-year-old stand into three over-mentioned groups. Discriminant analysis gives more precise results compared with PCA. In the analysed stand, the most important traits for the evaluation of biosocial position were diameter at breast height, crown projection area and height.

Abstract

In the study, the measurements of Scots pine height increments were used to compare the increments of pine trees of different age classes. All of the analyzed trees were growing in stands located on fresh mixed coniferous forest sites. The study concerned a 10-year period of growth of 8 tree age classes. Due to variation in climate conditions, all trees were studied over the same calendar period. Longitudinal analysis was used to compare different age classes of trees with reference to the increments in height. This procedure had not been previously used for such purpose. The results obtained did not confirm the hypothesis of parallel profiles implying that there existed differences in the growth of trees in various age groups.

Abstract

The current problems related to air pollution in Europe, but also in Poland, are forcing the search for solutions aimed at significantly reducing the amount of solid particles harmful to humans in the air. Road transport is responsible for almost half of the pollution, as it releases nitrogen oxides into the air. In view of the above, the authors of the article want to turn attention toward methane as a fuel alternative traditional ones, pointing to the possibility of its use by Poland and presenting its advantages and disadvantages.

Abstract

Annual height increments are a very important characteristic of Scots pine. They have a direct effect on the determination of the dendrometric properties of a stand, such as volume increment. In the present study the data concern height increments of the main shoot in selected age classes of trees (age 72 to 92 years). A relationship is determined between the values of the increments and meteorological conditions such as temperature, precipitation and sunshine. On the basis of lasso regression analysis, precipitation in the year preceding the incremental season was shown to have the greatest effect on height increments of Scots pine.

Summary

A method of discriminant variable determination was used to visualize the division of oak trees into Kraft classes. Usual discriminant variables and several types of kernel discriminant variables were studied. For this purpose the traits of oak (Quercus L.) trees, measured on standing trees, were used. These traits included height of tree, breast height diameter and crown projection area. The use of the Gaussian kernel and modified Gaussian kernel enabled the clearest division into Kraft classes. In particular, the latter method proved to be the most effective.

Proces oczyszczania się pni dębu szypułkowego (Quercus robur L.) a pierśnica drzew w drzewostanach gospodarczych