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1
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Porównanie metod szacowania pozyskaniowych szkód glebowych na przykładzie rębnego drzewostanu bukowego

100%
Kulak D.
Leśne Prace Badawcze
|
2014
|
tom 75
|
nr 3
2

Możliwość określenia rodzaju środka zrywkowego na podstawie rozmiaru i charakteru naruszeń wierzchniej warstwy gleby

100%
Kulak D.
Acta Agraria et Silvestria. Series Silvestris
|
2010
|
tom 48
The present work makes an attempt to recognize the kind of logrolling means used while logging on the basis of range of disturbances of the top soil layer. The investigation covered horse skidding and skidding made with the MultiFKS hoisting winch. Graphical analysis of the diagrams representing disturbances characteristics of the top soil layer (surface and volume) allows one to perform correct recognition of the causative factor responsible for 18% of the damages. Application of artificial neuron networks allowed us to correct typing-out logging environment for 75-96.8% disturbances of the top soil layer.
3
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Wplyw wybranych srodkow zrywkowych na uszkodzenia gleby w rebnych drzewostanach bukowo-jodlowych

63%
Kulak D., Barszcz A.
Sylwan
|
2008
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tom 152
|
nr 12
20-28
4
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Rozmiar i charakter naruszeń wierzchniej warstwy gleby powstałych podczas pozyskiwania drewna w trzebieżowym drzewostanie jodłowym

63%
Kulak D., Senczyszyn L.
Sylwan
|
2011
|
tom 155
|
nr 08
5

The assessment of the level of energy expenditure of forest workers dislodging trees hang during early thinning

63%
Sowa J. M., Kulak D.
Zeszyty Naukowe Akademii Rolniczej w Krakowie. Sesja Naukowa
|
2005
|
tom 91
367-373
6
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Uszkodzenia drzew i odnowienia w wyniku trzebieży wczesnych w wybranych drzewostanach jodłowych

63%
Stanczykiewicz A., Kulak D.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
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2014
|
tom 16
|
nr 2B[39]
7
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Klasyfikacja ekotypowa samcow sarny europejskiej [Capreolus capreolus L.] na podstawie wybranych pomiarow ich ciala

63%
Kulak D., Wajdzik M.
Sylwan
|
2009
|
tom 153
|
nr 08
563-574
8
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Kosztochłonność pozyskania drewna harwesterem w drzewostanach przebudowywanych z zastosowaniem cięć częściowych

63%
Szewczyk G., Kulak D.
Sylwan
|
2013
|
tom 157
|
nr 04
Paper presents the results of research on the productivity and economic effectiveness of timber harvesting in stands managed under complex cutting systems. Use of the operating time of a work−shift, including wood processing, loads preparation for skidding and changes at work sites, was low and amounted to 0.62. The main categories of the operating time were delimbing (45%) and travelling (31%). The unit costs of work of a harvester in the analysed stands were higher amounting to 69 PLN/m3 for eight−hour shifts and 110 working days a year, and 40 PLN/m3 for sixteen−hour shifts compared to the work of the saw operator (32 PLN/m3 for the eight−hour shift).
9

Morphological characteristics of hairs in the roe deer (Capreolous capreolus Linnaeus, 1758) from the Polish part of the Carpathian Mountains

63%
Kulak D., Wajdzik M.
Electronic Journal of Polish Agricultural Universities. Series: Forestry
|
2006
|
tom 09
|
nr 4
10
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Wydajność zrywki drewna skiderem na terenach pochyłych

51%
Kulak D., Stanczykiewicz A., Szewczyk G., Wala L.
Sylwan
|
2019
|
tom 163
|
nr 07
The aim of the study is to characterise the working time structure of an operator of the LKT 82 skidder performing timber skidding on the sloping area, and to develop models of efficiency and time−consumption of the work depending on selected factors characteristic of the described transport process. The research was performed in the Sucha Forest District (S Poland). We considered two treatments: late thinning and felling performed in stands with the dominating share of beech. Logs obtained with chainsaws were initially extracted with horses and laid at the slope road. Later on the additional skidding with skidder tractor was done. Continuous timing of individual operations was performed with the use of a microcomputer equipped with time measurement software (accuracy of 1 second). We also determined skidding distance using a GPS device, the number of extracted logs in the load, and the volume of the logs. The total timing measurements lasted for a total of 70 h 24 min 27 s. During that time, the tractor made 72 cycles, transporting 998 logs with a total volume of 493.3 m³. In the mature stand, the average skidding distance amounted to approximately 1,160 m, a single load consisted of 3−4 logs with a volume of 7.7 m³. The operational efficiency of the skidding was 9.1 m³/h. In the thinning stand, the skidding distance was 1,230 m, the average load consisted of 22 logs with a volume of 5.8 m³. The operational efficiency amounted to 7.8 m³/h, on average. The working time structure was dominated by auxiliary (over 60%) and effective (nearly 30%) times. The obtained regression models of the duration of activities from the group of operational times were characterised by high correlation coefficient (about 0.75 for skidding time and driving without a load). Relatively strong relationships (r > 0.5) were also found between the times of collecting cable pulling and load attachment, and the volume of the extracted loads, and in the case of the times of collecting cable pulling also the type of treatment performed. The regression models for the times of log stacking, pulling the loads up with the winch and detaching them, despite the fact that they were statistically significant, characterised by relatively low correlation coefficients. The relationship between skidding efficiency and skidding distance was also determined (fig.). The duration of skidding cycles was described using the multiple regression with the volume of single loads and the skidding distance as the determinants. The regression models of skidding efficiency and time−consumption of skidding cycles may find practical application in estimating the efficiency of the tasks performed in stands and under conditions similar to those analysed in the present research.
11
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Rozmiar i charakter naruszeń wierzchniej warstwy gleby powstałych podczas pozyskiwania i zrywki drewna w trzebieżach wczesnych drzewostanów świerkowych

51%
Sowa J., Kulak D., Stanczykiewicz A., Szewczyk G.
Sylwan
|
2011
|
tom 155
|
nr 05
12
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Czasochłonność zrywki drewna skiderem z drzewostanu do szlaku operacyjnego

51%
Szewczyk G., Kulak D., Stanczykiewicz A.
Sylwan
|
2020
|
tom 164
|
nr 04
Skidders are used at two stages of log extraction: when pulling logs to a skid trail and for further semi−suspended log skidding along the trail to a landing. The aim of the study is to characterise the working time structure of a skidder operator performing timber extraction from the stand to the trail, and to develop time−consumption models depending on terrain slope and skidding distance. The research was done in stands situated in central and southern Poland, where late thinning and cutting in areas between tree groups (group clear cut) were performed. The timber was transported to skid trails by means of LKT 82 cable skidders. The timber was pulled to the trail on slopes with inclinations ranging from –30° (up the slope) via 0° (on a flat surface) to 38° (down the slope) at a maximum distance of 70 m. Time study of work cycles was performed and the volume of timber harvested in each package was calculated. Analyses of working time and its time consumption were performed for the operational working time. The measurements covered a total of 269 log extraction cycles with a total duration of over 20 hours. Altogether 752 logs with a total volume of over 520 m³ were extracted. The large share of time was devoted to load attaching and detaching (40%). Quite a large share of log extraction (24%) was associated with the long skidding distances. The time of stretching the collecting rope in the case of skidding up the slope (an average of 60 s) was significantly shorter than in the flat terrain or skidding down the slope (70 s). The average duration of a skidding cycle was also affected by the direction of the slope. Rectilinear relationships were determined between the duration of a skidding cycle and the terrain slope, as well as the skidding distance. The combined effect of these features on the duration of skidding was described. The duration of a skidding cycle was influenced by distance (61% of the general variability) more than the slope (16%). The time consumption of the skidding amounted to ca 12 min/m³. Two homogeneous groups were determined: uphill skidding as well as skidding in flat terrain and downhill. The relationship between the time consumption and the number of logs extracted along with their volume took the form of an exponential regression. The time consumption standard of log extraction performed with the use of a skidder along a skid trail should be supplemented with the time of forming timber packages in the stand and pulling them to the trail, with an additional distinction between the direction of skidding and terrain slope.
13

Damages to the surface layer of soil during timber harvesting using the equipment aggregated with farm tractors

51%
Kulak D., Sowa J. M., Stanczykiewicz A., Szewczyk G.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2012
|
tom 11
|
nr 2
In the study, impact of three devices aggregated with farm tractors on forest soil was compared – FRANSGARD 6000 GS cable winch and two processors – NIAB 5-15 and HYPRO 450. The basic difference between the above mentioned machines consists in the fact that the cable winch skids debranched tree stems while processors skid the whole trees, including their tree-tops. The percentage of soil injured in late pine stand thinning reached, respectively: 1.2%, 2.2% and 5.5%. The analysis of significance of differences in Ug indicators characterising the damages induced has shown that only the indicator computed for HYPRO processor is significantly higher than the others. However, as the simulation performed has confirmed, appropriate thickening of skidding routes enables to achieve a comparable level of damages for all the machines examined. Taking into account the impact on forest soil, application of processors aggregated with farm tractors can be recommended for thinning stands.
14

Multifactor analysis of time consumption in manipulation and cutting stacked wood into length

51%
Szewczyk G., Sowa J. M., Kulak D., Stanczykiewicz A.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2012
|
tom 11
|
nr 2
Cutting stacked wood into length by means of a petrol chainsaw is a typical technical and technological wood harvesting solution. Due to the fact that wood harvesting is most commonly performed with the use of Tree-Length-System (TLS) or Long-Length-System (LLS), cutting into length in Poland is performed either after the first stage of skidding stems or logs to the skidding route or after the second stage of transportation, that is at the depot. Research was carried out in depots, during early and late thinnings of pine, fir, spruce and beech stands by means of manipulation and cutting into lengths using petrol chainsaws (Table 1). The aim of the study was to specify time consumption on the basis of the relativeness of EST = f (category of harvesting, roller’s length, chosen elements of the working day structure). Continuous time-motion analysis was carried out, according to the classification presented in Table 2. After completing harvesting, the produced material was received. Figure 1 presents the percentage of work activities observed in operational time. Performing cutting into length activities at a discussed working site resulted in high time percentage in case of T12 and T22 times. Table 3 presents the average values of time consumption correlated in terms of soft and hard wood species in the categories of early and late thinning stands. Some statistically significant differences in labour consumption levels have been demonstrated in case of specific stands and harvesting technologies. One multiple regression equation has been estimated – for early and late thinning. The regression model has been expressed by a formula (1). The equation parameters have been compiled in Table 4. Research results point to the relation between time consumption, the specific elements of the time structure of a working day, and the length of produced rollers expressing variable volume of produced rollers.
15

Rozmiar i rozmieszczenie naruszeń wierzchnich warstw gleby przy zrywce konnej w trzebieżach wczesnych drzewostanów jodłowych

51%
Kulak D., Szewczyk G., Stanczykiewicz A.
Nauka Przyroda Technologie. Uniwersytet Przyrodniczy w Poznaniu
|
2014
|
tom 08
|
nr 1
16

Wpływ zrywki drewna z użyciem siągników typu skider na uszkodzenia gleby w górskich drzewostanach jodłowo-bukowych

51%
Kulak D., Stanczykiewicz A., Szewczyk G., Kobialka P.
Forestry Letters
|
2013
|
tom 105
17

Podstawy metodyczne waloryzacji uzupełnijących czasów pracy w operacjach pozyskiwania i zrywki drewna

51%
Szewczyk G., Sowa J., Kulak D., Stanczykiewicz A.
Forestry Letters
|
2013
|
tom 105
18

Związki struktury dnia roboczego z fizjologiczną gotowością do pracy na stanowisku operatora pilarki spalinowej

51%
Sowa J. M., Kulak D., Leszczynski K., Szewczyk G.
Prace Komisji Nauk Rolniczych i Komisji Nauk Leśnych. Poznańskie Towarzystwo Przyjaciół Nauk
|
2007
|
tom 101
19
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Analiza struktury czasu pracy przy pielęgnacji upraw wykaszarkami spalinowymi

51%
Sowa J. M., Szewczyk G., Kulak D., Pasiowiec W.
Zeszyty Problemowe Postępów Nauk Rolniczych
|
2002
|
tom 486
|
nr 1
Together with the growth of young trees cultivation carried out by the National Forestry Board it became necessary to mechanize the works that would increase their efficiency with equally high quality. Recognition and optimalization of worktime structure of brush cutter operators during cultivation is of great practical importance in this context. Technological improvement of cultivation in the analysed experiment applied a square method (fig. 1), while technical rationalisation consisted in cutting around young trees. The worktime structure of the described workstand was defined with the help of a working day photography being taken for three days for four workers. Next the measured time data were classified according to a scheme from fig. l. A relatively high fraction of resting time and maintenance of the brush cutter in a workshift proved that an exploitation shift time coefficient of effectiveness was 0.61. On the basis of differences between effective worktime and rest distributions as well as technological stand-still and everyday maintenance it was presumed that the cause of frequent work breaks were repeated repairs of brush cutters.(fig. 6). High value of coefficient of operating time efficiency (0.93) proved the optimum choice of the applied technology. The work efficiency assumed for the experiment - three times higher than for a hand tool -indicates that it is necessary to turn to a hand-machine level of cultivating.
20

Jakość osobnicza kozłów pozyskanych w okręgu krakowskim w drodze odstrzału selekcyjnego

51%
Wajdzik M., Kubacki T., Kulak D.
Zachodni Poradnik Łowiecki. Kwartalnik Wojewódzkiego Sejmiku Łowieckiego w Poznaniu
|
2007-2008
|
nr 1[21]
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