Electronics and Telecommunications Research Institute

Jae Woong Yoon

Seung Koo Park

Bong Je Park

Suntak Park

Eun Jin Shin

Kyo Il Chung

Young Woong Kim

Kwang Han Park

Sungryul Yun

Chang Hee Jung

Mee Jeong Choi

Byung G No

An embodiment of the inventive concept provides a method of manufacturing a polymer film, the method including: preparing a first copolymer containing a first functional group; preparing a second copolymer containing a second functional group; preparing a first compound containing a third functional group; and performing a cross-linking reaction by mixing the first copolymer, the second copolymer, and the first compound, wherein the cross-linking reaction includes a reaction of the first functional group and the second functional group and a reaction of the second functional group and the third functional group, the first compound includes a polar group and any one group selected from among a vinyl group, an aryl group, and an acrylate group, and the third functional group has reactivity with respect to the second functional group, but does not have reactivity with respect to the first functional group.

Method of manufacturing polymer film and polymer film composition

Provided is focal variable device system including a focus variable element including an absorbing layer, and an adjustable light source configured to cause an adjustable light to enter the focus variable element. The absorbing layer includes a thermal expansion material that absorbs the adjustable light and thermally expands.

Focal variable device system

A method for detecting a fine frequency deviation generated in a transmission line such as a general public telephone switching network. The method includes the steps of transmitting test signals to a transmission channel to be tested, receiving the test signals from the transmission channel, detecting a basic period from the received test signals, and determining a measure period on the basis of the detected basic period, performing a normalization by use of the basic period determined, extracting values of signals to be calculated, namely, object signals from those of the basic and measure periods, calculating respective absolute values of the object signals, averaging the calculated absolute values, and thereby calculating an absolute value of frequency deviation and determining a sign or direction of the frequency deviation, and determining a final frequency deviation on the basis of the sign determined from the absolute value of frequency deviation.

Method for detecting fine frequency deviation

Growing community of inventors

Yongin, South Korea

Jae Woong Yoon