In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC （heating ventilation and air conditioning） u...In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC （heating ventilation and air conditioning） units. We chose R32 refrigerant, with its lower LCCP （life cycle climate performance） as a more sustainable choice than R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for R32. Moreover, high discharge gas temperature decreases the reliability of the compressor, and makes a large overheating loss increase. In this study, we will describe the technologies （reducing the piston pressurizing force, heat-insulating structure, optimizing the port diameter） that were developed to overcome these drawbacks. We will also oresent the performance and reliability of the newly develoned high efficiency swing, comnressor series for R32 refrigerant.展开更多
Cassava （Manihot esculenta Crantz） is globally known for its versatility. Its demand in the global market has increased in recent times. Many scholars have opined that the development of this root crop will boost ru...Cassava （Manihot esculenta Crantz） is globally known for its versatility. Its demand in the global market has increased in recent times. Many scholars have opined that the development of this root crop will boost rural economy especially in developing economies. This study investigates the production of cassava in Nigeria using different mechanization levels, which include： Hand Tools Technology （HTT）, Draught Animal Technology （DAT） and Engine Powered Technology （EPT）. These levels are classified into, low level mechanization, fair level mechanization and high level mechanization. The results show that the level of mechanization was high, only in land preparation while spraying, stem-cutting and weeding have low mechanization level. This shows that there are many unacceptable machines and suggests that efforts should be made to encourage cassava production considering the high economic, social and medical importance.展开更多
Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobi...Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobile robot and obstacles. But in case of active moving obstacle, many components and information need to process since their moving trace should be considered in real time. This paper mobile robot＇s driving algorithm of unknown dynamic envirormaent in order to drive intelligently to destination using ultrasonic and Global Positional Systern （GPS）. Sensors adjusted the placement dependment on driving of robot, and the robot plans the evasion method according to obstacle which are detected by sensors. The robot saves GPS coordinate of complex obstacle. If there are many repeated driving, robot creates new obstacles to the hr, ation by itself. And then it drives to the destination resolving a large range of local minirmnn point If it needs an intelligent circtmtantial decision, a proposed algorithm is suited for effective obstacle avoidance and arrival at the destination by performing simulations.展开更多
In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positio...In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positioning System （GPS） technology and motion-triggered cameras to test predictions of land-tenure territoriality and the resource dispersion hypothesis in a territorial carnivore, the puma Puma concolor. We documented 89 independent GPS interactions, 60% of which occurred at puma kills （n=53）, 59 camera interactions, 11 （17%） of which captured courtship behaviors, and 5 other interactions （1 F-F, 3 M-F, and 1 M-M）. Mean minimum weekly contact rates were 5.5 times higher in winter, the season when elk Cervus elaphus were aggregated at lower elevations and during which puma courtship primarily occurred. In winter, contacts rates were 0.6_＋ 0.3 （standard devi- ation （SD）） interactions/week vs. 0.1 _＋ 0.1 （SD） interactions/week during summer. The preponder- ance of interactions at food sources supported the resource dispersion hypothesis, which predicts that resource fluxes can explain temporary social behaviors that do not result in any apparent benefits for the individuals involved. Conspecific tolerance is logical when a prey is so large that the predator that killed it cannot consume it entirely, and thus, the costs of tolerating a conspecific sharing the kill are less than the potential costs associated with defending it and being injured. Puma aggregations at kills numbered as high as 9, emphasizing the need for future research on what explains tolerance among solitary carnivores.展开更多
文摘In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC （heating ventilation and air conditioning） units. We chose R32 refrigerant, with its lower LCCP （life cycle climate performance） as a more sustainable choice than R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for R32. Moreover, high discharge gas temperature decreases the reliability of the compressor, and makes a large overheating loss increase. In this study, we will describe the technologies （reducing the piston pressurizing force, heat-insulating structure, optimizing the port diameter） that were developed to overcome these drawbacks. We will also oresent the performance and reliability of the newly develoned high efficiency swing, comnressor series for R32 refrigerant.
文摘Cassava （Manihot esculenta Crantz） is globally known for its versatility. Its demand in the global market has increased in recent times. Many scholars have opined that the development of this root crop will boost rural economy especially in developing economies. This study investigates the production of cassava in Nigeria using different mechanization levels, which include： Hand Tools Technology （HTT）, Draught Animal Technology （DAT） and Engine Powered Technology （EPT）. These levels are classified into, low level mechanization, fair level mechanization and high level mechanization. The results show that the level of mechanization was high, only in land preparation while spraying, stem-cutting and weeding have low mechanization level. This shows that there are many unacceptable machines and suggests that efforts should be made to encourage cassava production considering the high economic, social and medical importance.
基金supported by the MKE(The Ministry of Knowledge Economy),Koreathe ITRC(Information Technology Research Center)support program(NIPA-2010-C1090-1021-0010)
文摘Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobile robot and obstacles. But in case of active moving obstacle, many components and information need to process since their moving trace should be considered in real time. This paper mobile robot＇s driving algorithm of unknown dynamic envirormaent in order to drive intelligently to destination using ultrasonic and Global Positional Systern （GPS）. Sensors adjusted the placement dependment on driving of robot, and the robot plans the evasion method according to obstacle which are detected by sensors. The robot saves GPS coordinate of complex obstacle. If there are many repeated driving, robot creates new obstacles to the hr, ation by itself. And then it drives to the destination resolving a large range of local minirmnn point If it needs an intelligent circtmtantial decision, a proposed algorithm is suited for effective obstacle avoidance and arrival at the destination by performing simulations.
文摘In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positioning System （GPS） technology and motion-triggered cameras to test predictions of land-tenure territoriality and the resource dispersion hypothesis in a territorial carnivore, the puma Puma concolor. We documented 89 independent GPS interactions, 60% of which occurred at puma kills （n=53）, 59 camera interactions, 11 （17%） of which captured courtship behaviors, and 5 other interactions （1 F-F, 3 M-F, and 1 M-M）. Mean minimum weekly contact rates were 5.5 times higher in winter, the season when elk Cervus elaphus were aggregated at lower elevations and during which puma courtship primarily occurred. In winter, contacts rates were 0.6_＋ 0.3 （standard devi- ation （SD）） interactions/week vs. 0.1 _＋ 0.1 （SD） interactions/week during summer. The preponder- ance of interactions at food sources supported the resource dispersion hypothesis, which predicts that resource fluxes can explain temporary social behaviors that do not result in any apparent benefits for the individuals involved. Conspecific tolerance is logical when a prey is so large that the predator that killed it cannot consume it entirely, and thus, the costs of tolerating a conspecific sharing the kill are less than the potential costs associated with defending it and being injured. Puma aggregations at kills numbered as high as 9, emphasizing the need for future research on what explains tolerance among solitary carnivores.
