Provided is an operational transconductance amplifier (OTA). An existing Nauta transconductor used to implement a high frequency Gm-C filter integrated circuit (IC) is analyzed by a new method and from a new perspective to remove extra components and divide roles of remaining inverters for more simple and efficient circuit structure. In an existing Nauta transconductor, a common mode signal from an input terminal is amplified and appears at an output terminal, while in the inventive Nauta transconductor the common mode signal from an input terminal does not appear at the output terminal and is effectively eliminated. These enhanced characteristics can be achieved with a smaller number of inverters than an existing Nauta transconductor. Frequency characteristics of the filter can be effectively enhanced by independently controlling the quality factor without affecting the transconductance value required for frequency characteristics of the filter.

A media access control (MAC) apparatus and corresponding methods for guaranteeing quality-of-service in a wireless local area network (LAN) are presented. The MAC method includes the steps of extracting, performing, determining, a first transmitting step, and a second transmitting step. The extracting step includes extracting a user priority from a frame received from an upper layer and separately storing a voice frame and a non-voice frame according to an access category (AC). The performing step includes independently performing backoff operations for the voice frame and the non-voice frame. The determining step includes determining whether the backoff operations for the voice frame and the non-voice frame have simultaneously ended. The first transmitting step includes transmitting the voice frame having a higher priority first and performing the backoff operation for the non-voice frame if the backoff operations have simultaneously ended. The second transmitting step includes transmitting a frame whose backoff operation ends if the backoff operations have not simultaneously ended.

A data hashing method, a data processing method, and a data processing system using a similarity-based hashing (SBH) algorithm in which the same hash value is calculated for the same data and the more similar data, the smaller difference in the generated hash values. The data hashing method includes receiving computerized data, and generating a hash value of the computerized data using the SBH algorithm in which two data are the same if calculated hash values are the same and two data are similar if the difference of calculated hash values is small, wherein a search, comparison, and classification of data may be quickly processed within a time complexity of O(1) or O(n) since the similarity/closeness of data content are quantified by component values for each of the respective corresponding generated hash values.

A turbo TCM decoder for performing a soft decision without performing a sector phase quantization is disclosed. The turbo TCM decoder includes: a symbol transformer for converting a received signal to signal bits of QPSK mode by using an I-axis coordinate and a Q-axis coordinate on a constellation of the received signal; a phase sector quantizer for performing a phase sector quantization or the received signal by using the I-axis coordinate and the Q-axis coordinate; a first decoder for determining coded data by decoding the converted signal bits; a delay for delaying the quantized signal; and a second decoder for determining un-coded data by using the delayed quantized signal and the determined coded data.

Conventional optoconductive compounds, such as CIS or CdTe include scarce indium or environmentally-unfriendly cadmium. On the other hand, an optoconductive compound according to the present invention has high optoconductive efficiency without inclusion of indium and cadmium, wherein the optoconductive compound according to the present invention is represented by AXYY' where A is a Group 11 element, X is a Group 15 element, and Y and Y' are Group 16 elements in which Y and Y' can be identical to or different from each other.