Abstract: A polyurethane fiber and a manufacturing method thereof are provided. The manufacturing method includes the following steps. A polyurethane material is provided. Then a melt extrusion process is carried out on the polyurethane material through a spinneret. The spinneret includes at least one spinneret orifice unit embedded in a spinneret body. Wherein, the spinneret orifice unit includes a plurality of spinneret sub-orifices, and each spinneret sub-orifice penetrates through the spinneret body. Each spinneret sub-orifice has a sub-orifice diameter ranging from 0.07 mm to 0.12 mm, and there is a sticking space between every two adjacent spinneret sub-orifices ranging from 0.01 mm to 0.05 mm. Then the polyurethane material passes through the spinneret sub-orifices and is sticked together to form the polyurethane fiber.

Abstract: A method for generating a codebook based on a discrete cosine transform, suitable for an electronic device with a plurality of antennas is provided, including: generating an identity matrix, and the size of the identity matrix is related to the number of antennas of the electronic device; inputting a plurality of column vectors of the identity matrix into a discrete cosine transform formula to calculate a plurality of codeword elements corresponding to the column vectors; generating a plurality of codewords corresponding to the column vectors, the codewords corresponding to the column vectors comprise the codeword elements corresponding to the column vectors; multiplying the codewords by a coefficient related to the number of antennas; determining whether the calculation of all the codewords has been completed; and completing the codebook.

Abstract: The disclosure provides an electronic device including a coupler, a transceiver, and a control circuit. The coupler generates a coupled downlink signal according to a downlink signal from a head-end unit. The transceiver switches between the transmission of a downlink signal and the reception of an uplink signal according to a control signal. The control circuit receives the coupled downlink signal, generates a status counting signal according to the power status of the coupled downlink signal, and generates the control signal according to the status counting signal. Only when the level of the coupled downlink signal is lower than an amplitude threshold level with a duration longer than a status counting time, the control circuit converts the status counting signal from a first logic level to a second logic level opposite to the first logic level. Otherwise, the control circuit maintains the status counting signal on the first logic level.

Abstract: A method for assisting with the transmission of TCP packets, which is used in a wireless communication system, including: receiving a plurality of TCP packets from a TCP packet sender and transmitting the TCP packets to a receiver proxy; transmitting a feedback packet to a sender proxy when receiving a TCP packet; calculating a round trip time (RTT) between the sender proxy and the receiver proxy when receiving the feedback packet, and comparing a RTT threshold and the RTT between the sender proxy and receiver proxy; determining whether a network between the sender proxy and the receiver proxy is in a congestion state according to the result of the comparison between the RTT threshold and the RTT; and dropping a TCP packet when the network is in the congestion state.

Abstract: The disclosure provides an electronic device including a coupler, a transceiver, and a control circuit. The coupler generates a coupled downlink signal according to a downlink signal from a head-end unit. The transceiver switches between the transmission of a downlink signal and the reception of an uplink signal according to a control signal. The control circuit receives the coupled downlink signal, generates a status counting signal according to the power status of the coupled downlink signal, and generates the control signal according to the status counting signal. Only when the level of the coupled downlink signal is lower than an amplitude threshold level with a duration longer than a status counting time, the control circuit converts the status counting signal from a first logic level to a second logic level opposite to the first logic level. Otherwise, the control circuit maintains the status counting signal on the first logic level.

Abstract: A manufacturing method of a waterproof and breathable shoe has a step of preparing a mold. Then, the mold is soaked into the rubber material, and the rubber material can cohere to a surface of the mold. Then, the rubber material cohering to the surface of the mold is dried to form into a thin and integrally molded shoe body on the surface of the mold. Then, an inside layer is combined with the shoe body. Then, the inside layer and the shoe body are reversed inside out and stripped off from the mold at the same time. Finally, the sole is combined with a bottom of the shoe body to form the waterproof and breathable shoe. Therefore, the shoe can provide a waterproof and breathable effect.