Electronics and Telecommunications Research Institute

Korea Research Institute of Standards and Science

Samchully Pharm. Co.,ltd.

Yong-tae Kim

Kwang-Ok Kim

Sung-Chang Kim

Dong-soo Lee

Hark Yoo

Kwang-Joon Kim

Bong-Tae Kim

Kyung-Il Kim

Kyeong-Eun Han

Bin-Yeong Yoon

Il Doh

Kyeong-Hwan Doo

Seung-Hwan Kim

Geun-Yong Kim

Kye-Hyun Ahn

Man-soo Han

Bin-yeong Yoon

Seung-Bum Ha

Sung-hoon Kwak

Geun-yong Kim

Mun-seob Lee

Kyung-min Baik

Se-hwa Kim

Jong-deog Kim

Bong-kyu Kim

Le Quan

Moon-jae Jho

Sung-soo Jung

Bong-young Ahn

Ho-chul Kim

Yong-hyeon Yun

Jae-Hoon Jeon

Soon-Jeong Kwon

Ji-Suk Yun

Jae-yub Hyun

The present invention relates to an ultra-thin acoustic lens for subwavelength focusing in a megasonic range and a design method thereof. More particularly, the present invention relates to a super-oscillatory planar ultra-thin acoustic lens for subwavelength focusing in the megasonic range, which includes a plurality of concentric regions arranged in a concentric shape with reference to the center point, wherein the concentric regions include a plurality acoustic insulation region for insulating incident acoustic waves, and a plurality of transmission regions for transmitting acoustic waves, the acoustic insulation regions and the transmission regions being formed alternatively in a radial direction from the center point so as to focus incident acoustic wave energy onto a subwavelength region. The acoustic lens has flat surfaces on both sides thereof respectively and has a plate shape having a constant thickness, and a layout, which is a radius of each of the plurality of acoustic insulation regions and transmission regions in the concentric region, is determined by a topology optimization reverse design method.

Ultra-thin acoustic lens for subwavelength focusing in megasonic range, and design method therefor

A gigabit passive optical network (GPON) system for fiber to the home (FTTH) service must provide a down-stream data rate of an optical band to provide IPTV service with hundreds of channels to subscribers, and must be able to provide an upstream data rate of an optical band using a currently available BM-IC chip. A currently available BM-IC chip for a GPON has 1.244 Gbps and 2.488 Gbps modes. Accordingly, an optical network terminal (ONT) for a GPON that is capable of providing a downstream transmission band of 10-Gbps and an upstream transmission band of 1.244 Gbps or 2.488 Gbps, and a method for processing an upstream frame in the terminal, are provided. The GPON ONT can provide 20 Mbps, high-definition IPTV service with 500 channels and can provide both upstream data rates of 1.244 Gbps and 2.488 Gbps according to a user's selection without using an additional device.

Optical network terminal of the gigabit passive optical network and frame treatment method of the ONT

Provided are an apparatus and method for efficiently and dynamically allocating a bandwidth on a Time Division Multiple Access-based Passive Optical Network (TDMA PON). The dynamic bandwidth allocation apparatus for uplink data transmission of a plurality of Optical Network Units (ONUs) including a plurality of class queues corresponding to Transmission Container (T-CONT) types, the plurality of ONUs connected to an Optical Line Terminal (OLT) on a Passive Optical Network (PON), includes: a class queue information storage unit storing information regarding a bandwidth allocation period and an allocatable bandwidth amount for each T-CONT type; an allocation check table unit checking the bandwidth allocation period for the T-CONT type received from the class queue information storage unit, and determining an allocatable bandwidth amount for the T-CONT type; and a bandwidth allocation unit allocating an uplink bandwidth to the T-CONT type with reference to the bandwidth allocation period and the allocatable bandwidth amount for the T-CONT type, and re-allocating to each ONU an uplink bandwidth remaining after allocating a total uplink bandwidths to all T-CONT types.

Apparatus and method for efficient bandwidth allocation on time division multiple access-based passive optical network (TDMA-PON)

A performance inspection system for an array ultrasound transducer includes: a driver for selectively applying an electric signal to all or some parts of constituent channels of the array ultrasound transducer; an acoustic power measurement unit for measuring an ultrasound acoustic power emitted from individual channels receiving the same voltage from the driver; a radiation conductance conversion unit for measuring a voltage signal applied to each channel although the driver applies different voltages to the individual channels, and converting the measured voltage into an ultrasound acoustic power acquired when the same voltage is applied to the channels; and a channel uniformity estimation unit for estimating uniformity of the acoustic power value acquired by the radiation conductance conversion unit or uniformity of acoustic power values of the individual channels measured under the same voltage.

System for testing performance of array ultrasound transducer

An Ethernet device having multiple lanes and a method of operating the lanes are provided. In one general aspect, it is possible to allocate a dummy block to each of one or more lanes such that the lanes do not selectively participate in communications. In addition, on a receiving side, the dummy block can be removed from among the genuine data blocks to enable data to be decoded. In this case, an Ethernet device on a transmission side and an Ethernet device on a receiving side can exchange information of a lane to which the dummy block is allocated by use of a lane status message, and the lane status message may be based on a link fault message specified by Ethernet standards.

Ethernet device and lane operating method

Provided is an automatic optical power control method for an optical line terminal (OLT) of a passive optical network (PON). The automatic optical power control method includes at the OLT, measuring an allowable range of the optical power allowing a normal network operation on the PON, at the OLT, setting an optimum optical signal level within the measured allowable range of the optical power, and at the OLT, adjusting a power level of a transmitter to the set optimum optical signal level. Accordingly, an appropriate power level can be selected depending on an optical distribution network (ODN) structure to drive the transmitter. Also, when the entire optical network units are deactivated, a laser of the transmitter is turned off to thereby minimize unnecessary power consumption at the OLT.

Automatic optical power control method for OLT in PON

A method of preparing 2-deoxy-L-ribose represented by the following formula I is disclosed. The preparation method includes the steps of: treating L-arabinose with an alcohol solvent in the presence of an acid to prepare 1-alkoxy-L-arabinopyranose; allowing the prepared 1-alkoxy-L-arabinopyranose to react with acyl chloride so as to prepare 1-alkoxy-2,3,4-triacyl-L-arabinopyranose; brominating the alkoxy group of the prepared 1-alkoxy-2,3,4-triacyl-L-arabinopyranose to prepare a 1-bromo-2,3,4-triacyl compound; allowing the prepared compound to react with zinc in the presence of ethyl acetate and an organic base so as to prepare glycal; treating the glycal with an alcohol solvent in the presence of an acid to prepare 1-alkoxy-2-deoxy-3,4-diacyl-L-ribopyranose; treating the prepared 1-alkoxy-2-deoxy-3,4-diacyl-L-ribopyranose with a base to prepare 1-alkoxy-2-deoxy-L-ribopyranose; and hydrolyzing the prepared 1-alkoxy-2-deoxy-L-ribopyranose in the presence of an acid catalyst.

Preparation method of 2-deoxy-L-ribose

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Daejeon, South Korea

Yong-tae Kim