This paper is a surve of the development and current state of occupational health andsafety in Chinese forestry and a general introduction to the administrative system and structure ofworking health and safety in the ...This paper is a surve of the development and current state of occupational health andsafety in Chinese forestry and a general introduction to the administrative system and structure ofworking health and safety in the Chinese forestry system.It also describes some accomplishments ofthe administrative units of forestry occupatiomal safety in recent decades and the important roles ofinvestigation and research in forestry accidents.Some suggestions and schemes for developing scientif-ic research on occupational health and safety its application in forestry production are presented.展开更多
An empirical time study was cohducted to evaluate the performance of the current felling and tree processing methods used in Northern Iran＇s Hyrcanian forest. Motor-manual felling is done mostly in winter, while tree...An empirical time study was cohducted to evaluate the performance of the current felling and tree processing methods used in Northern Iran＇s Hyrcanian forest. Motor-manual felling is done mostly in winter, while tree processing starts when the felling season ends. We identified the elements of felling and processing work phases, and 142 cycles and 110 cycles were respectively recorded for felling and processing. On the basis of data analysis （time study）, we developed statistical models of effective time consumption in the respective work phase and for its total productivity. The production rate of felling with and without delay time was 9.7 and 11.65 trees per hour （0.17 USD.m^-3 and 0.21 USD-m^-3）, and the average production cost with and without delay was 1.21 USD and 1.45 USD per tree, respectively. The average productivity of processing was 35 m^3 per effective hour and the average unit cost of processing was 0.92 USD.m^-3.展开更多
Amongst all forest utilization phases, harvesting plays a key role as the beginning phase of the utilization cycle and has a significant effect on the following phases.In this research, in order to examine the reducti...Amongst all forest utilization phases, harvesting plays a key role as the beginning phase of the utilization cycle and has a significant effect on the following phases.In this research, in order to examine the reduction of costs with respect to present and planned operations, the starting time of the harvesting or cutting phase and work flow were recorded. The starting time of each phase of the entire operation was recorded as well. Before harvesting the marked tree, the appropriate felling direction was determined and the azimuth of the correct direction was taken.The results indicate that there was not a meaningful relationship between the differences in direction of a leaning tree compared with the felling direction. However, there was a significant relationship between the difference of the defined and felling direction and the difference in tree leaning and defined direction. The same trend was observed between tree leaning and felling directions and tree leaning and defined directions. On the other hand,there was no significant relationship between tree leaning and felling directions and the defined and tree felling directions. In addition, this research shows that with an increase in tree volume, the time for tree cutting rose.Furthermore, when the difference of tree leaning and felling direction decreased, the time to cut the tree declined.The regression equation is Y = 168.9–0.14（the difference between tree leaning and felling direction） ＋ 0.7（volume）.展开更多
We define and study the Extended Feline Josephus Game, a game in which n players, each with ℓlives, stand in a circle. The game proceeds by alternating between hitting k consecutive players—each of whom wil...We define and study the Extended Feline Josephus Game, a game in which n players, each with ℓlives, stand in a circle. The game proceeds by alternating between hitting k consecutive players—each of whom will consequently lose a life—and skipping s consecutive players. This cycle continues until every player except one loses all of their lives. Given the nonnegative integer parameters n, k, s and ℓ, the goal of the game is to identify the surviving player. In this paper, we show how the defining parameters n, k, s, and ℓaffect the survivor of games with specific constraints on those parameters and our main results provide new closed formulas to determine the survivor of these Extended Feline Josephus Games. Moreover, for cases where these formulas do not apply, we provide recursive formulas for reducing the initial game to other games with smaller parameter values. For the interested reader, we present a variety of directions for future work in this area, including an extension which considers players lying on a general graph, rather than on a circle.展开更多
Staff members use chainsaws to remove a tree toppled by flooding in Dinghu District of Zhaoqing City,Guangdong Province,on August 6.That same day,the National Commission for Disaster Prevention,Reduction and Relief in...Staff members use chainsaws to remove a tree toppled by flooding in Dinghu District of Zhaoqing City,Guangdong Province,on August 6.That same day,the National Commission for Disaster Prevention,Reduction and Relief initiated an emergency response in Guangdong after heavy rainfall had caused severe flooding.China faces a high risk of floods,storm and hail-related disasters in August,as all seven major river basins in the country have entered the flood season.展开更多
文摘This paper is a surve of the development and current state of occupational health andsafety in Chinese forestry and a general introduction to the administrative system and structure ofworking health and safety in the Chinese forestry system.It also describes some accomplishments ofthe administrative units of forestry occupatiomal safety in recent decades and the important roles ofinvestigation and research in forestry accidents.Some suggestions and schemes for developing scientif-ic research on occupational health and safety its application in forestry production are presented.
基金financially supported by Iranian Ministry of Science, Research and Technologies and University of Joensuu
文摘An empirical time study was cohducted to evaluate the performance of the current felling and tree processing methods used in Northern Iran＇s Hyrcanian forest. Motor-manual felling is done mostly in winter, while tree processing starts when the felling season ends. We identified the elements of felling and processing work phases, and 142 cycles and 110 cycles were respectively recorded for felling and processing. On the basis of data analysis （time study）, we developed statistical models of effective time consumption in the respective work phase and for its total productivity. The production rate of felling with and without delay time was 9.7 and 11.65 trees per hour （0.17 USD.m^-3 and 0.21 USD-m^-3）, and the average production cost with and without delay was 1.21 USD and 1.45 USD per tree, respectively. The average productivity of processing was 35 m^3 per effective hour and the average unit cost of processing was 0.92 USD.m^-3.
文摘Amongst all forest utilization phases, harvesting plays a key role as the beginning phase of the utilization cycle and has a significant effect on the following phases.In this research, in order to examine the reduction of costs with respect to present and planned operations, the starting time of the harvesting or cutting phase and work flow were recorded. The starting time of each phase of the entire operation was recorded as well. Before harvesting the marked tree, the appropriate felling direction was determined and the azimuth of the correct direction was taken.The results indicate that there was not a meaningful relationship between the differences in direction of a leaning tree compared with the felling direction. However, there was a significant relationship between the difference of the defined and felling direction and the difference in tree leaning and defined direction. The same trend was observed between tree leaning and felling directions and tree leaning and defined directions. On the other hand,there was no significant relationship between tree leaning and felling directions and the defined and tree felling directions. In addition, this research shows that with an increase in tree volume, the time for tree cutting rose.Furthermore, when the difference of tree leaning and felling direction decreased, the time to cut the tree declined.The regression equation is Y = 168.9–0.14（the difference between tree leaning and felling direction） ＋ 0.7（volume）.
文摘We define and study the Extended Feline Josephus Game, a game in which n players, each with ℓlives, stand in a circle. The game proceeds by alternating between hitting k consecutive players—each of whom will consequently lose a life—and skipping s consecutive players. This cycle continues until every player except one loses all of their lives. Given the nonnegative integer parameters n, k, s and ℓ, the goal of the game is to identify the surviving player. In this paper, we show how the defining parameters n, k, s, and ℓaffect the survivor of games with specific constraints on those parameters and our main results provide new closed formulas to determine the survivor of these Extended Feline Josephus Games. Moreover, for cases where these formulas do not apply, we provide recursive formulas for reducing the initial game to other games with smaller parameter values. For the interested reader, we present a variety of directions for future work in this area, including an extension which considers players lying on a general graph, rather than on a circle.
文摘Staff members use chainsaws to remove a tree toppled by flooding in Dinghu District of Zhaoqing City,Guangdong Province,on August 6.That same day,the National Commission for Disaster Prevention,Reduction and Relief initiated an emergency response in Guangdong after heavy rainfall had caused severe flooding.China faces a high risk of floods,storm and hail-related disasters in August,as all seven major river basins in the country have entered the flood season.
