Engineering
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KAIST Research Team Discovers Process for Rapid Growth of N-Doped CNT Arrays
A team of scientists led by Profs. Sang-Ouk Kim, Won-Jong Lee and Duck-Hyun Lee of the Department of Materials Science and Engineering has found a straightforward process for rapid growth of wall-number selected, nitrogen-doped carbon nanotube (CNT) arrays, university officials said on Monday (March 16).
KAIST researchers prepared highly uniform nanopatterned iron catalyst arrays by tilted deposition through block copolymer nanotemplates. This remarkably fast growth of highly uniform N-doped CNTs, whose material properties and chemical functionalizability are reinforced by N-doping, offers a new area of a large-scale nanofabrication, potentially useful for diverse nano-devices.
Carbon nanotubes (CNTs) are of broad technical interest in electronics, photonics, energy devices, and other applications. However, establishing a straightforward process for mass production of uniform CNTs with desired structure and properties has been a long-standing challenge.
In particular, it was strongly desired to precisely control the numbers of walls and diameter of CNTs, which are decisive parameters for the physical properties of CNTs. In this respect, the preparation of monodisperse catalyst array having a narrow size distribution is generally considered an effective pathway to produce well-defined CNTs, since the number of walls and diameter of the produced CNTs are closely related to the catalyst size.
The finding was featured in the March 13 edition of Nano Letters, a leading journal in the nano technology field.
2009.03.20 View 13137 -
Workshop on Biomedical IC to Be Held on March 26
KAIST will hold a workshop on "biomedical IC for future healthcare system" on March 26 at a lecture room of the School of Electrical Engineering & Computer Science. The workshop is organized by SEECS and the Korean Institute of Next Generation Computing.
At the workshop, a variety of new technologies expected to expedite the development of biomedical systems will be presented. KAIST Prof. Hoi-Jun Yoo will speak on the "body channel communication" using the human body as the signal transmission medium and Dr. Seung-Hwan Kim of Electronics and Telecommunications Research Institute (ETRI) on a wearable vital sign monitoring system.
Other subjects are CMOS (complementary metal-oxide semiconductor) fully electronic biosensor for biomolecular detection to be presented by KAIST Prof. Gyu-Hyeong Cho; nerve interface and IC (integrated circuit) system design by KAIST Prof. Yoon-gi Nam; design of neural recording and stimulation IC using time-varying magnetic field by KAIST Prof. Seong-Hwan Cho; low power multi-core digital signal processor for hearing aid by Dong-Wook Kim, senior researcher at the Samsung Advanced Institute of Technology; and a non-contact cardiac sensor by KAIST Prof. Seung-Chul Hong.
With the advent of the ageing society, medical expenses of the elderly people are rapidly increasing. As a way to address the issue, interests are growing in "ubiquitous healthcare," a technology that uses a large number of environmental and patient sensors and actuators to monitor and improve patients’ physical and mental condition.
The upcoming workshop is the first academic event on biomedical integrated chips to be held in Korea. The workshop will provide a valuable opportunity for experts in biomedical area to get together and examine the present status of Korean biomedical area and discuss about its future, KAIST officials said.
2009.03.20 View 16591
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KAIST Wins First Prize at Recon Challenge of Int"l Magnetic Resonance Society
Professor Jong-chul Ye of the Department of Bio and Brain Engineering and Hong Jeong, a doctorate student, won the first prize at the Recon Challenge held as part of a workshop sponsored by the International Society for Magnetic Resonance in Medicine (ISMRM) held in Sedona, the United States.
The workshop took place under the theme of “data sampling and image reconstruction” on Jan. 25-28 in Sedona, Arizona, the United States. The KAIST team beat out major magnetic resonance imaging groups from the U.S. and Europe.
The Recon Challenge is a biennial competition highlighting different reconstruction strategies and metrics to compare them. ISMRM is an international, nonprofit, scientific association which promotes communication, research, development, and applications in the field of magnetic resonance in medicine and biology and other related topics.
At the competition, the KAIST team presented a new dynamic MRI algorithm called k-t FOCUSS that is optimal from a compressed sensing perspective. The main contribution of the method is extension of k-t FOCUSS to a more general framework with prediction and residual encoding. The prediction provides an initial estimate while the residual encoding takes care of the remaining residual signals.
2009.02.06 View 12825 -
Prof. Cho Identifies Dynamics of Signal Transportation System in Control of Cell Proliferation
KAIST, Jan. 22, 2009 -- A research team led by Prof. Kwang-Hyun Cho of the Department of Bio and Brain Engineering, KAIST, has identified a hidden mechanism of the dynamic behavior of signal transportation system involved in the control of cell proliferation, university authorities said.
The finding is expected to provide a clue to appropriately controlling the pathway of ERK protein which is known to play a significant role in causing and spreading cancer. The research was featured as the cover paper of the latest online edition of the Journal of Cell Science.
The Ras-Raf-MEK-ERK pathway (or ERK pathway) is an important signal transduction system involved in the control of cell proliferation, survival and differentiation. However, the dynamic regulation of the pathway by positive- and negative-feedback mechanism, in particular the functional role of Raf kinase inhibitor protein (RKIP) are still incompletely understood. RKIP is a physiological endogenous inhibitor of MEK phosphorylation by Raf kinases, but also participates in a positive-feedback loop in which ERK can inactivate RKIP.
"We attempted to unearth the hidden dynamics of these feedback mechanisms and to identify the functional role of RKIP through combined efforts of biochemical experiments and computer simulations based on an experimentally validated mechanical model," Prof. Cho was quoted as saying.
2009.02.03 View 11152 -
Prof. Seong Publishes English Book on Reliability in Digital Control Systems
Prof. Poong-Hyun Seong of Department of Nuclear and Quantum Engineering has recently published an English-language book on reliability and risk issues in large scale safety-critical digital control systems used in complex facilities such as nuclear power plants.
The book entitled “Reliability and Risk Issues in Large Scale Safety-critical Digital Control Systems” is a result of Prof. Seong’s collaboration with some KAIST graduates who used to be under his guidance. The 303-page publication has been published by Springer, one of the world’s leading publishers of academic journals, as part of the Springer Series in Reliability Engineering.
The book consists of four parts; part I deals with issues related to hardware, part II software, part III human factors and finally the last part integrated systems. It can be purchased through some on-line book stores such as Amazon.com.
Prof. Seong served as an editor-in-chief for Nuclear Engineering and Technology (NET), an international journal of Korean Nuclear Society (KNS), from 2003 to 2008. He also worked as a chair of the Human Factors Division (HFD) of American Nuclear Society (ANS) from 2006 to 2007. Prof. Seong is now a commissioner of Korea Nuclear Safety Commission which is the nation’s highest committee on Nuclear Safety.
2008.12.26 View 14996
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KAIST Scientists Creates Transparent Memory Chip
--See-Through Semis Could Revolutionize Displays
A group of KAIST scientists led by Prof. Jae-Woo Park and Koeng-Su Lim has created a working computer chip that is almost completely clear -- the first of its kind.
The new chip, called "transparent resistive random access memory (TRRAM), is similar in type to an existing technology known as complementary metal-oxide semiconductor (CMOS) memory -- common commercial chips that provide the data storage for USB flash drives and other devices. Like CMOS devices, the new chip provides "non-volatile" memory, meaning that it stores digital information without losing data when it is powered off. Unlike CMOS devices, however, the new TRRAM chip is almost completely clear.
The paper on the new technology, entitled "Transparent resistive random access memory and its characteristics for non-volatile resistive switching," was published in the December issue of the Applied Physics Letters (APL), and the American Institute of Physics, the publisher of APL, issued a press release about this breakthrough.
"It is a new milestone of transparent electronic systems," says researcher Jung-Won Seo, who is the first author of the paper. "By integrating TRRAM devices with other transparent electronic components, we can create a totally see-through embedded electronic system."
Technically, TRRAM devices rely upon an existing technology known as resistive random access memory (RRAM), which is already in commercial development for future electronic data storage devices. RRAM is built using metal oxide materials between equally transparent electrodes and substrates.
According to the research team, TRRAM devices are easy to fabricate and may be commercially available in just 3-4 years.
"We are sure that TRRAM will become one of alternative devices to current CMOS-based flash memory in the near future after its reliability is proven and once any manufacturing issues are solved," says Prof. Jae-Woo Park, who is the co-author on the paper. He adds that the new devices have the potential to be manufactured cheaply because any transparent materials can be utilized as substrate and electrode. They also may not require incorporating rare elements such as Indium.
2008.12.17 View 15863 -
Prof. Cho Wins Best Paper Award
KAIST Prof. Nam-Zin Cho of the Department of Nuclear and Quantum Engineering, won the Best Thesis Award in the nuclear reactor physics category at the 2008 Winter Meeting of the American Nuclear Society held on Nov. 9-13 in Reno, Nevada.
His paper, entitled "Thermal Feedback Transient Analysis of a Pebble Fuel Based on the Two-Temperature Homogenized Model," was jointly authored by Hwi Yu and Jong-Un Kim under the guidance of Prof. Cho.
Prof. Cho was elected a fellow of the American Nuclear Society in 2001 and has served as the deputy editor of the Nuclear Science and Engineering, the research journal of the American Nuclear Society, since 1999.
2008.12.09 View 13311 -
Prof. Kim's Team Wins Silver Prize at International Design Contest
A KAIST team led by Prof. Myung-Suk Kim of the Department of Industrial Design won a silver prize (given by the Mayor of Osaka) at the 17th International Design Competition held at the Osaka International Convention Center on Nov. 27.
The team, made up of KAIST students Da-Woon Chung (representative), Ji-Hoon Kim and Bo-Yeon Kim, presented a sonic energy absorbing (SONEA) system to transform noise energy into electrical energy. At the 2008 competition held under the main theme of "Earth-Life: Clean Aqua, Clean Air, Clean Energy," a Chinese team won the gold prize, Japanese and Korean groups shared silver prizes, and bronze prizes were given to U.S. and German contestants.
It was noteworthy that the KAIST team was the only undergraduate contestants who won the prize. Ji-hoon Kim had already won a bronze prize last year at the same competition.
The International Design Competition Osaka has been held annually or biannually, organized by the Japan Design Foundation, since 1983 and is considered as one of the most prestigious design competitions.
2008.12.09 View 14453 -
Prof. Kwon Unveils Home-Made Lunar Module
A KAIST research team led by Prof. Se-Jin Kwon at the Department of Aerospace Engineering has unveiled a small lunar module developed in cooperation with engineers at a local company, Space Solutions, university authorities said on Thursday (Nov. 27).
The home-made lunar module, the vehicle that conducts survey on the surface of the moon, is 40 centimeters tall and weighs 25 kg. Equipped with a liquid-fuel rocket engine with a maximum thrust of 350 newtons (N), it is capable of carrying objects weighing around 20 kg to the lunar space from the space ship. Professor Kwon"s team held a demonstration of the lander for journalists at a KAIST lab on Friday (Nov. 28).
Lunar landers are critical in developing lunar spacecraft, and countries with advanced aerospace technologies have been careful to protect their core technologies.
According to Prof. Kwon, every part of the rocket engine, including the catalyst, was home made. The rocket"s propulsion system features a state-of-the-art propellant valve developed by Space Solutions, which enables thrust control.
Lunar modules between the 100 and 200 kilogram range, developed by NASA (U.S. National Aeronautics and Space Administration), costs around $100 million, said Kwon. "It is expensive to guarantee the safety of developers of an American module because the fuel contains carcinogens. But the rocket engine created by KAIST team could cut development costs to about half that because it is powered by environmentally friendly fuel," he said.
The lander, product of a six-year-long effort, represents remarkable advancement in the technology for developing spacecraft for lunar missions.
2008.12.01 View 11283 -
2008 IEEE International Conference on Humanoid Robots Opens
The 2008 IEEE-RAS International Conference on Humanoid Robots, an international gathering to identify new research trends and technology in humanoid robotics, will open a three-day session on Monday (Dec. 1) at the Hotel Rivera and KAIST in Daejeon.
The annual conference is organized by KAIST and the Robotics and Automation Society of the Institute for Electric and Electronic Engineers, a U.S.-based international non-profit, professional organization for the advancement of technology related to electricity.
The conference is expected to draw a total of 200 robotics researchers from 19 different countries. Prof. Jun-Ho Oh, at the Department of Mechanical Engineering who led the creation of Korea"s first humanoid robot Hubo, is serving as general chair of the conference. Prof. Oh was named the host of the 2008 conference at the 2007 conference held at the Carnegie Melon University of the United States. The eight-year old conference was inaugurated in Boston in 2000.
On the opening day of Dec. 1, seven lectures will be given on diverse areas of robotics including cognitive humanoid vision, and robot vision sensor and sensing. On the subsequent two days, a total of 110 papers will be presented.
During the conference period, a variety of robots produced by six local and foreign robot makers will be on demonstration, providing opportunities for researchers and industrial robot makers to share technological ideas.
Highlights of the conference will be special lectures by world-renowned robot researchers Prof. Yoshiyuki Sankai of University of Tsukuba, who has created an exoskeletal "robot suit," and Prof. Art Kuo of Univerity of Michigan who is regarded as a leading authority in dynamic walking.
Following the conference, all participants are scheduled to tour Prof. Oh"s Hubo Lab and the Human-Robot Interaction Research Center, both located at KAIST.
2008.12.01 View 12723
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KAIST Collaborating with U.S. Universities to Advance Humanoid Robotics
Hubo, a life-size walking bipedal humanoid robot, is perhaps the best-known character in Korea that KAIST has ever produced. It was shown to the government heads of the Asia-Pacific region during the APEC held in Busan, Korea, in 2005 and appeared at the hit concerts of the pop singer Jang-Hoon Kim. The humanoid robot is soon likely to catch the fancy of Americans as a U.S. government-funded project seeks to create a Hubo that can work and interact with people in collaboration with Korean scientists.
"We are going to give the brains to Hubo. (Japanese) Asimo can do only pre-programmed actions. We want to create a Hubo that can help people, interact with people," said Prof. Paul Oh of the Department of Mechanical Engineering & Mechanics at Drexel University in Philadelphia and leader of the five-year international project which was launched in November 2007.
The U.S.$2.5 million project is funded through the Partnership for International Research and Education (PIRE) Program of the National Science Foundation (NSF) of the United States. It brings together world-renowned experts in humanoid design and information technologies.
"Dr. Jun-Ho Oh"s lab at KAIST (that has created Hubo) is the world"s leader in humanoid design and the U.S. has advanced technologies in the areas such as artificial intelligence, mechanical learning and robot vision. Combining the strengths of the two countries can create a synergy effect and develop a more advanced humanoid robot," said Paul Oh. He is currently serving as Program Director of Robotics of the NSF which is overseeing robotics research (non-military) in the U.S. consisting over 150 robotics faculty.
Paul Oh"s research team consists of experts from five U.S. universities -- Drexel, Bryn Mawr College, Colby College, the University of Pennsylvania and Virginia Tech -- and KAIST.
Leading a delegation of six professors and eight students, Dr. Paul Oh made a two-day visit to KAIST on Nov. 18-19 to review the progress of the project and have a technical meeting with participants.
"The U.S. universities participating in this program are scattered across the nation. So we decided to have a technical meeting here in Korea," he said.
Asked the reason why he chose KAIST as a partner for the program, Dr. Oh said that KAIST is willing to open Hugo to international researchers, whereas in Japan only Honda engineers are allowed to touch Asimo, which is a humanoid robot created by Honda Motor Company.
The project is to establish no barrier for roboticists anywhere in the world to pursue the humanoid research; a suite of humanoid platforms will be available for researchers to develop and advance capabilities like locomotion and human-robot interaction.
The team has been initially involved in development of three tools, all of which are based on the Hubo platform, in order to kick-start humanoid research in the U.S. They are the Mini-Hubo (a small, light-weight and affordable humanoid purchasable at the price lower than $8,000), On-Line Hubo (a program to operate Hubo online) and Virtual Hubo (a simulation program to do researches in cyberspace). As the first outcome of the project, the Mini-Hubo is expected to be released in the U.S. around next April.
Another important purpose of the PIRE program is to seek transformative models to train scientists and engineers to effectively work in global multi-disciplined design teams. To this end, an aggregate number of 20 students from U.S. universities are to stay at the KAIST during the next five years, with two students taking turns on a six-month term.
"I was really amazed how much work is done with small funding here. This is really an excellent example to learn," said Roy Gross, an undergraduate from Drexel who has been staying at Prof. Oh"s Lab for the past three months.
2008.11.21 View 16383 -
Method to Synthesize New Lithium Ion Battery Cathode Material Identified
A KAIST research team headed by Prof. Do-Kyung Kim at the Department of Materials Science and Engineering developed a technology to synthesize a new lithium ion battery spinel cathode which is regarded as a core part of hybrid and lithium battery cars.
The research was conducted in collaboration with a research team of Prof. Yi Cui at Stanford University"s Department of Chemistry. Their findings were introduced in the November issue of Nano Letters, one of the leading academic journals in nano-science.
The newly synthesized lithium ion battery spinel cathode known as spinel LiMn2O4 nanorods is attracting interests as an alternative cathode material since it is a low-cost, environmentally friendly substance for Li-ion battery cathodes. Its raw material is also highly available.
Lithium ion batteries with high energy and power density are important for consumer electronic devices, portable power tools, and vehicle electrification. LixCoO2 is a commonly used cathode material in commercial lithium iron batteries. However, the high cost, toxicity, and limited abundance of cobalt have been recognized to be disadvantageous.
2008.11.20 View 11809