In recent years, with the deterioration of the global ecological environment and the change of people's lifestyle, allergic rhinitis (AR) has gradually become a common and frequently-occurring disease in otolaryng...In recent years, with the deterioration of the global ecological environment and the change of people's lifestyle, allergic rhinitis (AR) has gradually become a common and frequently-occurring disease in otolaryngology, and the risk of inducing asthma increases with the duration of rhinitis. According to some data, the incidence rate of AR is as high as 10%~25% in the world. The main clinical manifestations are nasal congestion, nasal itching, runny nose, sneezing and other nasal membrane inflammatory reactions, which affect the olfactory function, reduce the sleep quality and bring great inconvenience to people's daily life and work. It cannot be eradicated, so clinical treatment is usually focused on relieving acute symptoms, stabilizing the development of the disease and preventing relapse. In this paper, the common clinical treatments of AR are classified and analyzed.展开更多
NURBS curve is one of the most commonly used tools in CAD systems and geometric modeling for its various specialties, which means that its shape is locally adjustable as well as its continuity order, and it can repres...NURBS curve is one of the most commonly used tools in CAD systems and geometric modeling for its various specialties, which means that its shape is locally adjustable as well as its continuity order, and it can represent a conic curve precisely. But how to do degree reduction of NURBS curves in a fast and efficient way still remains a puzzling problem. By applying the theory of the best uniform approximation of Chebyshev polynomials and the explicit matrix representation of NURBS curves, this paper gives the necessary and sufficient condition for degree reducible NURBS curves in an explicit form. And a new way of doing degree reduction of NURBS curves is also presented, including the multi-degree reduction of a NURBS curve on each knot span and the multi-degree reduction of a whole NURBS curve. This method is easy to carry out, and only involves simple calculations. It provides a new way of doing degree reduction of NURBS curves, which can be widely used in computer graphics and industrial design.展开更多
文摘In recent years, with the deterioration of the global ecological environment and the change of people's lifestyle, allergic rhinitis (AR) has gradually become a common and frequently-occurring disease in otolaryngology, and the risk of inducing asthma increases with the duration of rhinitis. According to some data, the incidence rate of AR is as high as 10%~25% in the world. The main clinical manifestations are nasal congestion, nasal itching, runny nose, sneezing and other nasal membrane inflammatory reactions, which affect the olfactory function, reduce the sleep quality and bring great inconvenience to people's daily life and work. It cannot be eradicated, so clinical treatment is usually focused on relieving acute symptoms, stabilizing the development of the disease and preventing relapse. In this paper, the common clinical treatments of AR are classified and analyzed.
文摘NURBS curve is one of the most commonly used tools in CAD systems and geometric modeling for its various specialties, which means that its shape is locally adjustable as well as its continuity order, and it can represent a conic curve precisely. But how to do degree reduction of NURBS curves in a fast and efficient way still remains a puzzling problem. By applying the theory of the best uniform approximation of Chebyshev polynomials and the explicit matrix representation of NURBS curves, this paper gives the necessary and sufficient condition for degree reducible NURBS curves in an explicit form. And a new way of doing degree reduction of NURBS curves is also presented, including the multi-degree reduction of a NURBS curve on each knot span and the multi-degree reduction of a whole NURBS curve. This method is easy to carry out, and only involves simple calculations. It provides a new way of doing degree reduction of NURBS curves, which can be widely used in computer graphics and industrial design.
