Korea Advanced Institute of Science and Technology

Korea Institute of Machinery & Materials

Korea Institute of Science and Technology

Dohyun Kim

Yongdae Kim

Jiyeon Choi

Juhwan Noh

Sungil Kim

Song Min Kim

Hocheol Shin

Md Siam Uddin

Yong Won Song

Hee-Shin Kang

Jaehoon Kim

Young Hee Lee

Ji-Whan Noh

Kwangyun Jung

Hyojeong Yoo

Byeong Eun Kwak

Xuan Tung Hoang

Yujin Kwon

Sang Hoon Ahn

A femtosecond laser source according to an embodiment of the present invention includes: a pulse generator that converts a continuous wave laser into an optical pulse train; a burst generator that separates the optical pulse train into a plurality of burst pulses; a pulse amplification and spectral broadening unit that expands the spectrum by amplifying a plurality of burst pulses; and a pulse compressor that compresses a plurality of amplified burst pulses to generate a femtosecond laser with a pulse width of 1 picosecond (10s) or less.

Fiber-based high repetition rate femtosecond laser source and laser processing system including the same

Various embodiments provide carbon dots emitting light having multiple colors and a method of fabricating the same. According to various embodiments, the carbon dots include at least two structural characteristics. At least two emission levels indicative of different emission wavelengths, respectively, may be introduced into the carbon dots based on the structural characteristics. A ratio of emission colors of the carbon dots may be adjusted when the carbon dots are synthesized or after the carbon dots are synthesized.

Carbon dots emitting light having multiple colors and method of fabricating the same

A method for detecting a GPS spoofing attack using a difference between output values of a GPS receiver, which is generated due to inaccuracy of a GPS spoofer, and an apparatus therefor are provided. The method includes receiving a GPS signal; and determining the received GPS signal as a GPS satellite signal or a GPS spoofing signal using a learning model learned based on a difference between output values of a GPS receiver. The method further includes labeling and collecting dispersion degree data including a position, a speed, and a time output from the GPS receiver with whether the GPS signal is the GPS satellite signal or the GPS spoofing signal and modeling the learning model using the collected data.

Method for GPS spoofing detection with GPS receivers leveraging inaccuracies of GPS spoofing devices and apparatus therefore

Disclosed are an anti-drone method using a GPS spoofing signal and a system thereof. According to an embodiment of the inventive concept, an anti-drone method may include injecting a GPS spoofing signal to analyze a drone feature of a target drone and hijacking the target drone by injecting a GPS spoofing signal into the target drone based on a drone hijacking strategy corresponding to the analyzed drone feature among predefined drone hijacking strategies. The analyzing of the drone feature may include injecting the GPS spoofing signal to analyze a safety device mechanism (GPS fail-safe) and a path-following algorithm of the target drone.

Method for anti-drone using GPS spoofing signal and system therefore

The present disclosure discloses an optical device structure including an optical fiber including a core part, a clad part, and a three-dimensional micro hole structure in the clad part, wherein a surface of the three-dimensional micro hole structure is provided with at least a non-flat surface, and a conformal graphene layer is formed on the surface of the three-dimensional micro hole structure, and a method of manufacturing the same.

Structures in optical devices having graphene and manufacturing method for the same

A method for pruning perimeter walks includes: hashing a name or attributes of an event, when the event occurs, to figure out a destination location of the event; performing greedy forwarding of geographic routing so as to send a packet of the event towards the destination location; checking a distance D between the destination location and a current node where a packet transmission using greedy forwarding mode is impossible, when the packet reaches the current node; checking distances between the destination location and respective neighboring nodes of the current node to obtain a neighboring node having a minimum distance M, when the distance D between the current node and the destination location is same or less than half of radio transmission range; comparing the minimum distance M to the distance D; and determining which node is a rendezvous node, according to the comparison result.

Method for pruning perimeter walks in data-centric storage sensor networks

Growing community of inventors

Daejeon, South Korea

Dohyun Kim