We present eNav, a smartphone-based vehicular GPS navigation system that has an energy-saving location sensing mode capable of drastically reducing navigation energy needs. Traditional implementations sample the phone GPS at the highest possible rate (usually 1Hz) to ensure constant highest possible localization accuracy. This practice results in excessive phone battery consumption and reduces the attainable length of a navigation session. The seemingly most common solution would be to always use a car-charger and keep the phone plugged-in during navigation at all times. However, according to a comprehensive survey we conducted, only a small percent of people would actually always carry around their phones' car-chargers and cables, as doing so is inconvenient and defeats the true ''wireless'' nature of mobile phones. In addressing this problem, eNav exploits the phone's lower-energy on-board motion sensors for approximate location sensing when the vehicle is sufficiently far from the next navigation waypoint, using actual GPS sampling only when close. Our user study shows that, while remaining virtually transparent to users, eNav can reduce navigation energy consumption by over 80% without compromising navigation quality or user experience.
There are some misunderstandings in inquiry design in social studies textbooks.The compilers of textbooks often simply regard inquiry design as question or activity design.They boldly make inquiry design the major components of textbooks,but without an appropriate presentation of the procedure of inquiry.They pay attention to the demonstrability of inquiry design,but ignore its feasibility.All these misunderstandings root in the fact that textbook compilers do not make in-depth research on teaching theories of social studies and they don't have good understanding of teaching practice of social studies home and abroad,which lead to negative effects on teachers' inquiry teaching and students' inquiry learning.
We present eNav, a smartphone-based vehicular GPS navigation system that has an energy-saving location sensing mode capable of drastically reducing navigation energy needs. Traditional implementations sample the phone GPS at the highest possible rate (usually 1Hz) to ensure constant highest possible localization accuracy. This practice results in excessive phone battery consumption and reduces the attainable length of a navigation session. The seemingly most common solution would be to always use a car-charger and keep the phone plugged-in during navigation at all times. However, according to a comprehensive survey we conducted, only a small percent of people would actually always carry around their phones' car-chargers and cables, as doing so is inconvenient and defeats the true "wireless" nature of mobile phones. In addressing this problem, eNav exploits the phone's lower-energy on-board motion sensors for approximate location sensing when the vehicle is sufficiently far from the next navigation waypoint, using actual GPS sampling only when close. Our user study shows that, while remaining virtually transparent to users, eNav can reduce navigation energy consumption by over 80% without compromising navigation quality or user experience.
Coherent noise reduction in interferometers often involves a rotating diffuser. This paper describes technical details about a contactless method for characterizing and optimizing diffusers based on measuring scattered light in spatial frequency domain.
In the new round of curriculum reform,role playing has been paid attention by many history teachers.However,they lack the systematic understanding of the inner relation between role playing and the development of historical thinking.The functions of role playing in the development of historical thinking can be reflected in three aspects: firstly,role playing can help students understand historical concepts,so that they can know well of historical texts;secondly,role playing can help students reconstruct historical events,so that they can know the facts in history;finally,role playing provides great space for students to interpret history,which can help them seek for historical meaning.
History textbooks should highlight the in different dimensions so that students' imagination can be fully developed.Firstly,textbook can use imagination and fiction to arouse students' imagination in history narration.Secondly,textbook can use document,story writing and anti-fact imagination to consolidate students' imagination in activity design.Finally,textbook can use imaginary pictures,the photographs of historical relics and activity of drawing to enhance students' imagination.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
