Archives: 연구 > 연구성과

At the ISSCC (IEEE International Solid-State Circuit Conference), the most distinguished conference in the field of circuits, Ph.D. student Jin-Su Lee (Advised by Hoi-Jun Yoo) won the award of “Demonstration Session Certificate of Recognition”.
ISSCC 2020 was held in San Francisco, USA, from February 16th to February 20th.
The award details are as follows.
Award name: Demonstration Session Certificate of Recognition (Awarded to top two school-demos presented at ISSCC 2020)
Award winner: Ph.D. student Jin-Su Lee (Advised by Hoi-Jun Yoo)
This achievement is meaningful in that Professor Hoi-Jun Yoo’s lab has received the “Demonstration Session Certificate of Recognition” twice in a row, this year as well as last year.
Congratulations once again for the award of Ph.D. student Jin-Su Lee.

Professor Min-Kyu Je has been named as the ‘Distinguished Lecturer’ supported by the Circuits and Systems Society (CASS) of the Institute of Electrical and Electronics Engineers (IEEE). As the world’s largest society in the field of circuit and system, IEEE CASS selects a number of world-renowned scholars who lead research in this field with outstanding research results as ‘Distinguished Lecturers’ every year. The selected scholars get the opportunity to conduct guest lectures at more than 120 chapters around the world. 
This gives the members of the society a chance to gain knowledge of the latest research trends and outstanding achievements and to communicate directly with the Distinguished Lecturer.
Professor Min-Kyu Je has been recognized as an excellent researcher in the field of circuits and systems for next-generation medical devices and brain-neural interfaces. He will be working as a Distinguished Lecturer for two years from this year to 2021, and give out lectures on the theme of ‘integrated circuits and microsystems for biomedical applications’. A list of IEEE CASS Distinguished Lecturers can be found at the link below.
Congratulations again to Professor Min-Kyu Je!
[Link] https://ieee-cas.org/distinguished-lectures

Professor Jae-Hyouk Choi has been nominated as the Distinguished Lecturer of the IEEE Solid-State Circuits Society (SSCS). IEEE SSCS is the world’s largest integrated-circuit society with more than 10,000 members worldwide. IEEE SSCS is responsible for publishing and hosting the Journal of Solid-State Circuits (JSSC), IEEE Xplore’s largest downloaded journal, and the International Solid-State Circuits Conferences (ISSCC), the most authoritative conference in semiconductor circuits.  
IEEE SSCS selects about ten world-renowned scholars who lead research in this field with outstanding research results as ‘Distinguished Lecturers’ every year. This selection is more meaningful because the IEEE SSCS supports the selected distinguished researchers to travel around the world to give invited lectures and international conferences hosted by the IEEE, as well as at universities and research institutions around the world.
Professor Jae-Hyouk Choi was selected for his excellence in research in the field of RF/analog circuits for 5G and 6G communications. He will give a lecture on the subject of ‘Ultra-low-noise, high-frequency signal generation circuit research’, which is essential for the implementation of next-generation ultra-high-speed wired and wireless communication systems for two years from this year to 2021.
A list of current and past IEEE SSCS Distinguished Lecturers can be found at the link below.
Congratulations again to Professor Jae-Hyouk Choi!
[Link] https://sscs.ieee.org/dl-program/distinguished-lecturer-roster?highlight=WyJkbCIsImRsJ3MiLCJyb3N0ZXIiLCJkbCByb3N0ZXIiXQ==
     

Highly functional and free-form displays are critical components to complete the technological prowess of wearable electronics, robotics, and human-machine interfaces.

A KAIST team created stretchable OLEDs (Organic Light-Emitting Diodes) that are compliant and maintain their performance under high-strain deformation. Their stress-relief substrates have a unique structure and utilize pillar arrays to reduce the stress on the active areas of devices when strain is applied.

Traditional intrinsically stretchable OLEDs have commercial limitations due to their low efficiency in the electrical conductivity of the electrodes. In addition, previous geometrically stretchable OLEDs laminated to the elastic substrates with thin film devices lead to different pixel emissions of the devices from different peak sizes of the buckles.

To solve these problems, a research team led by Professor Kyung Cheol Choi designed a stretchable substrate system with surface relief island structures that relieve the stress at the locations of bridges in the devices. Their stretchable OLED devices contained an elastic substrate structure comprising bonded elastic pillars and bridges. A patterned upper substrate with bridges makes the rigid substrate stretchable, while the pillars decentralize the stress on the device.

Although various applications using micropillar arrays have been reported, it has not yet been reported how elastic pillar arrays can affect substrates by relieving the stress applied to those substrates upon stretching. Compared to results using similar layouts with conventional free-standing, flat substrates or island structures, their results with elastic pillar arrays show relatively low stress levels at both the bridges and plates when stretching the devices. They achieved stretchable RGB (red, green, blue) OLEDs and had no difficulties with material selection as practical processes were conducted with stress-relief substrates.

Their stretchable OLEDs were mechanically stable and have two-dimensional stretchability, which is superior to only one-direction stretchable electronics, opening the way for practical applications like wearable electronics and health monitoring systems.

Professor Choi said, “Our substrate design will impart flexibility into electronics technology development including semiconductor and circuit technologies. We look forward this new stretchable OLED lowering the barrier for entering the stretchable display market.”

This research was published in Nano Letters titled Two-Dimensionally Stretchable Organic Light-Emitting Diode with Elastic Pillar Arrays for Stress Relief. (https://dx.doi.org/10.1021/acs.nanolett.9b03657).  This work was supported by the Engineering Research Center of Excellence Program supported by the National Research Foundation of Korea.

Figure. Photographs of the patterned rigid part of the substrate on the finger joint indicating 2D dimensional stretchability and images of stretchable OLEDs on a finger joint emitting green light

School of EE recorded the most publications and awards at Humantech Paper Award for five years in a row.

Humantech Paper Award, which was the 26th at this time since 1994, is held by Samsung Electronics to find distinguished engineering in the discipline of science and technology.

At Humantech Paper Award, not only the individual prize but also a special prize is given to university or high school with notable accomplishment.

“The special prize for the most publications and awards,” which includes 10 million KRW, is the greatest honor among special prizes.

Moreover, it is recognizable that our department received this astonishing award for five years in a row.

We expect excellent achievements of KAIST EE are revealed extensively to improve the prestige.

Researchers described a new strategy of designing metamolecules that incorporates two independently controllable subwavelength meta-atoms. This two-parametric control of the metamolecule secures the complete control of both amplitude and the phase of light.
 
A KAIST research team in collaboration with the University of Wisconsin-Madison theoretically suggested a graphene-based active metasurface capable of independent amplitude and phase control of mid-infrared light. This research gives a new insight into modulating the mid-infrared wavefront with high resolution by solving the problem of the independent control of light amplitude and phase, which has remained a long-standing challenge.
 
Light modulation technology is essential for developing future optical devices such as holography, high-resolution imaging, and optical communication systems. Liquid crystals and a microelectromechanical system (MEMS) have previously been utilized to modulate light. However, both methods suffer from significantly limited driving speeds and unit pixel sizes larger than the diffraction limit, which consequently prevent their integration into photonic systems.
 
The metasurface platform is considered a strong candidate for the next generation of light modulation technology. Metasurfaces have optical properties that natural materials cannot have, and can overcome the limitations of conventional optical systems, such as forming a high-resolution image beyond the diffraction limit. In particular, the active metasurface is regarded as a technology with a wide range of applications due to its tunable optical characteristics with an electrical signal.
 
However, the previous active metasurfaces suffered from the inevitable correlation between light amplitude control and phase control. This problem is caused by the modulation mechanism of conventional metasurfaces. Conventional metasurfaces have been designed such that a metaatom only has one resonance condition, but a single resonant design inherently lacks the degrees of freedom to independently control the amplitude and phase of light.
 
The research team made a metaunit by combining two independently controllable metaatoms, dramatically improving the modulation range of active metasurfaces. The proposed metasurface can control the amplitude and phase of the mid-infrared light independently with a resolution beyond the diffraction limit, thus allowing complete control of the optical wavefront.
 
The research team theoretically confirmed the performance of the proposed active metasurface and the possibility of wavefront shaping using this design method. Furthermore, they developed an analytical method that can approximate the optical properties of metasurfaces without complex electromagnetic simulations. This analytical platform proposes a more intuitive and comprehensively applicable metasurface design guideline.
 
The proposed technology is expected to enable accurate wavefront shaping with a much higher spatial resolution than existing wavefront shaping technologies, which will be applied to active optical systems such as mid-infrared holography, high-speed beam steering devices that can be applied for LiDAR, and variable focus infrared lenses.
 
Professor Min Seok Jang commented, “This study showed the independent control amplitude and phase of light, which has been a long-standing quest in light modulator technology. The development of optical devices using complex wavefront control is expected to become more active in the future.”
 
MS candidate Sangjun Han and Dr. Seyoon Kim of the University of Wisconsin-Madison are the co-first authors of the research, which was published and selected as the front cover of the January 28 edition of ACS Nano titled “Complete complex amplitude modulation with electronically tunable graphene plasmonic metamolecules.”

 

This research was funded by the Samsung Research Funding & Incubation Center for Future Technology.

Professor Min-Soo Rhu received the “Facebook Faculty Research Award”, which is awarded by the Facebook headquarters. 167 faculty members from 100 universities in 26 countries around the world have applied for the award and 10 faculty members out of them earned the award. The significance of this award is that Professor Min-Soo Rhu is the only winner in Asia. It is also the first from KAIST.

Professor Min-Soo Rhu won the award in the “Systems for Machine Learning” area for his research titled “A Near-Memory Processing Architecture for Training Recommendation Systems”. He will receive a $50,000 prize money that can be used for research. The awarding ceremony will be held at the “AI Systems Faculty Summit” in fall 2020.

Congratulations again to Professor Min-Soo Rhu!

More information about the award can be found at the link below.   

[Link]

https://research.fb.com/blog/2020/02/announcing-the-winners-of-the-systems-for-machine-learning-rfp/

Professor Min-Soo Rhu’s lab has succeeded in developing an “AI-based recommendation technology” acceleration system and their work has been reported in the media. The system accelerates AI-based recommendation algorithms from 6x up to 17x.

The AI-based recommendation service refers to advertisement recommendations that can be found easily on portal sites such as Google and Naver. This is a service based on a deep learning system and recommends personalized information by using a user’s search history through AI technology. The key element of such service is the “computation time of the algorithm”. Since it is based on real-time information, the quality of the service is determined by how quickly the recommendation results are derived. Besides, this is directly related to user satisfaction and also the profit generation of the company.

Professor Min-Soo Rhu’s research team has devised a solution to effectively reduce execution time by developing an AI accelerator computing system based on memory, which improves the so-called ‘memory bottleneck’. The system proposed by the team is a ‘Processing in Memory (PI614M)’ technology that places an AI accelerator close to the memory. This is noteworthy in that it effectively reduces data transfers and memory access times.

The developed technology is receiving positive reviews and can be utilized in various fields. Professor Min-Soo Rhu has expressed his position to cooperate with domestic companies to win the leadership of the AI accelerator market.

The results of this research are globally recognized for their excellence, including to be listed on the 2019 IEEE Micro Top Picks – Honorable Mention List, which was presented in 26 of the most influential results among the hundreds of papers published in computer system architecture in 2019.

In the meantime, this research was carried out with the support from Samsung Electronics Future Technology Foundation. Congratulations on your achievements.

Our engineering school held the Readers’ Choice Award ceremony. In the ceremony, Professor Changho Suh and Professor Hyunjoo Lee were selected in 2019 spring and autumn, respectively.

The ceremony was at the council chamber of the engineering school on Jan 15th. Including Prof. Choongsik Bae and Prof. Sung-Yool Choi, who is the dean and the deputy head of the engineering school respectively, a cadre of professors participated in the ceremony.

Readers’ Choice Award is for a researcher who enhanced the reputation of the engineering school by promoting research achievement on ‘KAIST Breakthroughs’, which is a Research Webzine published from 2014.

This ceremony was secondly planned, and the best research achievement was voted among the articles which are published in 2019.

This is significantly meaningful because two winners belong to our department. We wish diverse accomplishment to be promoted for further notable articles. 

 

The research team of Professor Hyunchul Shim accomplished the 3rd place in the final of AlphaPilot Orlando Race held by Lockheed Martin on last Dec. 6th.

Lockheed Martin held AlphaPilot Orlando Race at the beginning of this year and awarded a million USD (1.2 billion KRW) to the race winner-drone which cruises fast on the intricate course. Over 420 teams challenged to participate in the final of the race, but only nine teams were selected for the final.

The research team of Prof. Shim was chosen confidently for the final as one of the nine teams among 420 teams who attended last April.

A drone race is already popular enough to be shown live by such as ESPN in the US. A participant wears a first-person view (FPV) goggle, which shows the real-time image transferred from the camera on the drone, for control.

Congratulations to Prof. Shim and his research team for the great accomplishment against distinguished teams.

Information related to the race and detail can be found through the link below.

 

[Link]

https://www.lockheedmartin.com/en-us/news/events/ai-innovation-challenge.html