Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Unbounded Perturbations of Nonlinear Second-Order Difference Equations at Resonance
SEMILINEAR PROBLEMS WITH BOUNDED NONLINEAR TERM
MARTIN SCHECHTER Received 17 August 2004
We solve boundary value problems for elliptic semilinear equations in which no asymptotic behavior is prescribed for the nonlinear term. 1. Introduction Many authors (beginning with Landesman and Lazer ) have studied resonance problems for semilinear elliptic partial diﬀerential equations of the form
−∆u − λ u = f (x,u)
u = 0 on ∂Ω,
where Ω is a smooth bounded domain in Rn , λ is an eigenvalue of the linear problem
−∆u = λu
u = 0 on ∂Ω,
Medical imaging has been transformed over the past 30 years by the advent
of computerized tomography (CT), magnetic resonance imaging (MRI), and
various advances in x-ray and ultrasonic techniques. An enabling force behind
this progress has been the (so far) exponentially increasing power of
computers, which has made it practical to explore fundamentally new approaches.
Servo compensation usually implies that some type of ﬁlter network such as lead/lag circuits or proportional, integral, or differential (PID) algorithms will be used to stabilize the servo drive. However, there are other types of compensation that can be used external to the servo drive to compensate for other things in the servo plant (machine) that can, for example, be structural resonances or nonlinearities such as lost motion or stiction. These machine compensation techniques are shown in Figure 1 and are valid for either hydraulic or electric servo drives.