Abstract: Aspects of the invention include systems and methods configured to prevent masquerading service attacks. A non-limiting example computer-implemented method includes sending, from a first server in a cloud environment, a communication request comprising an application programming interface (API) key and a first server identifier to an identity and access management (IAM) server of the cloud environment. The API key can be uniquely assigned by the IAM server to a first component of the first server. The first server receives a credential that includes a token for the first component and sends the credential to a second server. The second server sends the credential, a second server identifier, and an identifier for a second component of the second server to the IAM server. The second server receives an acknowledgment from the IAM server and sends the acknowledgment to the first server.

Abstract: Provided in the present invention is a bearing maintenance timing acquisition method: first, acquiring vibration signals of a bearing under different loads; then, respectively acquiring dimensionless parameters according to the vibration signal of each load; thus, acquiring predicted damage condition distribution data of the bearing under different loads according to the dimensionless parameters; and finally, obtaining accurate maintenance timing based on the predicted damage condition distribution data under different loads, so as to prolong the service life of the bearing while reducing maintenance costs.

Abstract: Provided in the present invention is a bearing maintenance timing acquisition method: acquiring vibration signals of a bearing under different loads; then, respectively acquiring dimensionless parameters according to the vibration signal of each load; thus, acquiring predicted damage condition distribution data of the bearing under different loads according to the dimensionless parameters; and finally, obtaining accurate maintenance timing based on the predicted damage condition distribution data under different loads, so as to prolong the service life of the bearing while reducing maintenance costs.

Abstract: A power amplifier includes a clamping circuit configured to provide a clamped voltage from a power supply; an amplifier pair having first inputs coupled to the clamping circuit, second inputs and an output for providing an amplified signal; and a biasing circuit coupled between the clamping circuit and the second inputs. The biasing circuit is configured to adjust input bias voltages of the amplifier pair such that the output of the amplifier pair varies proportionally to a change of the power supply.

Abstract: A power amplifier includes a clamping circuit configured to provide a clamped voltage from a power supply; an amplifier pair having first inputs coupled to the clamping circuit, second inputs and an output for providing an amplified signal; and a biasing circuit coupled between the clamping circuit and the second inputs. The biasing circuit is configured to adjust input bias voltages of the amplifier pair such that the bias voltage of the output of the amplifier pair varies proportionally to a change of the power supply.