Chong Kun Dang Corporation

Korea Advanced Institute of Science and Technology

Korea Telecommunication Authority

Chong Ryul Lee

Kyeong Bok Min

Sang Choon Lee

Hong Woo Lee

Hoi Choo Son

Hyo Sung Kwak

Eung Nam Kim

Jung Woo Kim

Soon Kil Ahn

Yong Kwan Park

Seung Min Ryu

Byeong Seon Jeong

Koo Hun Chung

Hoe Joo Son

Kyung Hoi Cha

Chong K Un

Sung Jo Choi

Nucleoside derivatives and process for preparing thereof

The present invention relates to a mercaptopyrrolidinyl derivative of the following formula ##STR1## suitable for the preparation of carbapenem compounds.

2- (2-Substituted pyrrolidin-4-yl) thio-carbapenem derivatives

2-(2-substituted pyrrolidin-4-yl) thio-carbapenem derivatives

The present invention relates to a method and system for synthesizing speech utilizing a periodic waveform decomposition and relocation coding scheme. According to the scheme, signals of voiced sound interval among original speech are decomposed into wavelets, each of which corresponds to a speech waveform for one period made by each glottal pulse. These wavelets are respectively coded and stored. The wavelets nearest to the positions where the wavelets are to be located are selected from stored wavelets and decoded. The decoded wavelets are superposed to each other such that original sound quality can be maintained and duration and pitch frequency of speech segment can be controlled arbitrarily.

Speech segment coding and pitch control methods for speech synthesis

A local area network system using a code division multiple access method is provided. The system includes a repeater for generating a reference synchronizing signal to synchronize the system, transceivers, connected to the repeater via a sending line and a receiving line, and subscriber units, connected to each transceiver. Each transceiver includes a common synchronizing circuit section for replicating and regenerating a synchronizing signal, as a reference signal, which is equal to the reference synchronizing signal generated by the repeater. Each transceiver also has a transmitter for delaying the synchronizing signal in accordance with the specific number of each subscriber unit and the delay time attributed to the sending and the receiving lines, multiplying the delayed synchronizing signal by the signal obtained by level coding the data sent by the transmitter into M-ary data, and then transmitting multiplied data to the sending line. Moreover, the transceiver has a receiver for delaying a reference synchronizing signal which is generated at the common synchronizing circuit section with the delay time corresponding to the specific number of the receiver, detecting the sent signal which corresponds to the subscriber units of the receiver after providing a correlation value in accordance with the delayed synchronizing signal, and converting the sent signal into original data by integrating the detected signal. Therefore, the users may simultaneously transmit their data over the same transmission lines without collision among their data. Also they may exchange information with each other without a central switchboard.

Local area network system utiliziing a code division multiple access

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Seoul, South Korea

Chong Ryul Lee