scholarly journals Predicting the Acceptance of Elastography Machine Technology

Author(s):  
Kadir Öymen HANÇERLİOĞULLARI
Keyword(s):  
2020 ◽  
Vol 62 (4) ◽  
pp. 258-269
Author(s):  
Krzysztof Kamiński ◽  
Grzegorz Szewczyk ◽  
Janusz Kocel

AbstractOne of the essential elements of work technology assessment is task performance time. In the working day structure, production times are crucial; however, under certain conditions, complementary work times can have a share of up to 30%. Accurate determination of the time structure of a work shift is very time consuming and requires time measurements using the methods of cumulative timing or snapshot observations. For this reason, the overall share of complementary work times in a work shift is usually estimated roughly, equally for all timber harvesting conditions. The aim of this study was to determine the impact of selected working environment factors on the share of complementary work times in a work shift, in technologies on the manual-machine and the machine levels. The analyses were carried out in 33 forest districts of the Regional Directorate of State Forests in Wrocław. Among forest contractors, surveys were carried out to analyse the time structure of a working day. For each forest district, analyses of environmental factors potentially relevant to the share of complementary work times in a work shift were carried out; these included field features, dispersion of stands, features of timber, area accessibility. The total share of complementary work times in the machine-level technology variant amounted to approx. 40% and was higher than the manual-machine technological variant, where this share amounted to approx. 35%. The models developed for standardization of the share of variability of complementary work times, in the case of the manual-machine technology level, took into account the share of timber assortments with the length of over 2.5 m as well as the share of upland and mountain sites. In the case of timber harvesting at the machine technology level, the standardization model included as significant the factors such as the share of coniferous forest sites, the number of forest complexes with an area of over 100 hectares, and the total length of roads. Therefore, the above features could be selected as decisive for the share of the complementary work time category out of the full set of environmental variables taken into consideration in the estimation of the time-consumption of timber harvesting processes.


1999 ◽  
Author(s):  
Shouri Yasui ◽  
Kazutoshi Sakai

Abstract The benefits of hardturning include reduced setup costs; shorter tool change times; improved squareness by virtue of the ability to machine cylinder I.D., O.D. and face in one chucking; low energy consumption and elimination of the need to handle grinding sludge and waste fluid. Hardturning has typically been used as a replacement for grinding, in the processing of fitting surfaces or clad surfaces, and other such relatively straightforward applications not requiring sliding. In recent years, however, due to advances in servo and other machine technology, and tool material improvements (CBN, ceramics), hardturning has entered the realm of finishing curved and complex shaped surfaces that have sliding and rolling contacts. This paper will present the machine characteristics developed to meet the ever increasing demand for hardturning process accuracy, and introduce each of the factors which ultimately affected the design of machine components, providing examples where appropriate.


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