only+one
-
New Catalyst for Synthesizing Chiral Molecules Selectively
(from left: Dr. Yoonsu Park and Professor Sukbok Chang from the Department of Chemistry)
Molecules in nature often have “twin” molecules that look identical. In particular, the twin molecules that look like mirror images to each other are called enantiomers. However, even though they have the same type and number of elements, these twin molecules exhibit completely different properties.
Professor Sukbok Chang and Dr. Yoonsu Park from the Department of Chemistry developed a new catalyst capable of selectively synthesizing only one of the two enantiomers. Using this catalyst, the have succeeded in manufacturing the chiral lactam, an essential ingredient in pharmaceuticals, from a hydrocarbon compound.
Enantiomerism or chirality is considered very important for drug development. Biomaterials, such as DNAs and proteins also have chiral properties, but they exhibit different physiological activities depending on the types of drugs. One type of the enantiomer could be useful while the other is toxic. Hence, the technology for selective synthesizing (i.e. asymmetric synthesis) is required, but it is still regarded as a great challenge faced by modern chemistry to date.
The researchers solved this problem by developing a new catalyst. Earlier they presented their research on developing an iridium catalyst that converts hydrocarbons into high value γ-lactam compounds, and published it in Science in March 2018. However, the developed catalyst still had a limitation that both types of enantiomers are obtained without selectivity.
In this study, they found that among dozens of other catalyst candidates, iridium catalysts with chiral diamine scaffolds were able to select the correct enantiomer with a selectivity of 99% or more. This novel catalyst can be used to synthesize the various chiral γ-lactam as required. A left-handed γ-lactam and a right-handed γ-lactam can be produced using a left-handed iridium catalyst and a right-handed iridium catalyst, respectively.
They analyzed the reason for the high selectivity through computational chemistry simulations. They identified that temporal hydrogen bonding occurred between the chiral diamine catalysts and the hydrocarbon compound during the reaction. As a result of the hydrogen bonding, the formation of the left-handed lactam was boosted.
With their new catalyst, they also succeeded in synthesizing chiral lactam compounds with different structures. By using inexpensive and readily available feedstock hydrocarbons, the researchers produced a group of chiral lactams in different shapes. As their chirality and diverse structures enable lactams to function as an active compound in the body for antibiotic, anti-inflammatory, or anti-tumoral functions, this study may facilitate the development of potential drugs in a more efficient and cheaper way.
Professor Chang said, “We hope that our research on selectively producing core units of effective drugs will lead to developing new drugs that demonstrate fewer side-effects and higher efficacy. There are also economic advantages of this research because it uses hydrocarbon compounds, which can be abundantly found in nature, to produce high-value raw materials.
This research was published in Nature Catalysis(10.1038/s41929-019-0230-x) on February 19, 2019.
Figure 1. Asymmetric formation of chiral γ-lactam
Figure 2. Outline of research outcome
2019.03.05 View 7588 -
New Arylation Inducing Reaction Developed
(Professor Chang(left) and Professor Baik)
KAIST researchers have identified a reaction mechanism that selectively introduces aryl groups at the desired position of a molecule at room temperature. A team, co-led by Professor Sukbok Chang and Mu-Hyun Baik of the Department of Chemistry, used an iridium catalyst for the reaction. The team also proved that the reaction proceeds by an unusual mechanism by employing computer simulations that were substantiated with targeted experimental probes.
Hydrocarbon is an omnipresent material in nature. But its low reactivity makes it difficult to process to value-added products at the room temperature. Thus, designing catalysts that can accelerate the reaction remains an important challenge in chemistry.
In particular, since most chemicals used in medicine, pharmacy, or material chemistry contain aryl groups, an effective reaction to selectively introduce the aryl group has been an area of intensive research in organic chemistry.
In order to introduce an aryl group into stable carbon-hydrogen (C-H) bond, activation of the C-H bond with a halogen atom or organic metal is required prior to the introduction of the aryl group, or C-H functionalization directly on C-H bond is needed. Direct functionalization is more effective and economical, but most reactions require harsh reaction conditions such as high temperature or excess additives. And adding the aryl fragment selectively to only one among the many possible sites in the molecule is difficult. The new catalyst developed by these KAIST researchers is highly selective.
This work is the latest example of a successful teamwork between experimental and theoretical research groups: Computer simulations revealed that traditional approaches to arylation required high energies because the intermediates produced during the reaction are too low in energy. Based on this insight, the researchers thought of changing the character of the intermediate by oxidizing it, which was predicted to be a great way of increasing the reactivity of the catalyst. Subsequent experimental work showed that this design strategy is highly effective resulting in unprecedented chemical transformations.
Professor Chang said, “We have been able to carry out location-selective arylation at room temperature, as well as identifying a new reaction pathway, different from the conventionally suggested mechanism.” He continued, “This research is significant for identifying the reaction pathway and developing a novel selective reaction method that does not require high temperature or additives based on the mechanistic understanding. This work is a triumph of rational design, rather than fortuitous discovery.” The research findings were published online in Nature Chemistry on December 11, 2017.
(Figure 1: X-ray crystal structure transmetallation intermediate)
(Figure 2: Correlation between oxidation state of intermediate and energy barrier required for reductive elimination of intermediate as calculated using density function from computational chemistry )
(Figure 3: Arylation mechanism using iridium catalyst as suggested by the research team)
2018.01.11 View 6026 -
2017 KAIST Tech Fair to Showcase Ten Cutting-Edge Technologies
KAIST will showcase the ten most cutting-edge technologies developed by KAIST faculty and researchers at the 2017 KAIST Tech Fair. The fair will be held on September 12 at the COEX in Seoul. The fair will bring companies, venture capitalists, and tech consultants from around the country to learn about the most commercially potential technology from KAIST.
The ten technologies, all already patented, will be highly relevant for the new industrial trends summed up by the Fourth Industrial Revolution. They include the fields of ICT, unmanned transportation, AI, robotics, IoT, nano, and big data.
The Technology Evaluation Committee, comprised of the heads of the departments at KAIST, patent lawyers, and venture capitalists, selected the ten technologies based on their applicability, innovativeness, and marketability. The selectees will be provided with various commercialization support and services including the manufacturing of prototypes, marketing consultation at home and abroad, as well as handling IPR issues, among others.
KAIST will hold an information session as well as consultations for successful technology commercialization as one of the innovative plans proposed by the KAIST President Sung-Chul Shin. This session will invite 200 entrepreneurs who are interested in the selected technologies.
Associate Vice President of University-Industry Cooperation Kyung Cheol Choi said, “Starting with the selection of 2017 top ten crucial technologies, KAIST will continue supporting technology marketing as well as its successful transfer. KAIST will make effort to carry out university-industry cooperation and find core patent technologies and project ideas in order to stimulate technology commercialization.”
The list of the ten critical patent technologies selected by KAIST is as follows:
▶ Catalyst-Decorated Nanofiber Sensor for Health Monitoring
By Professor Il-Doo Kim (Department of Materials Science and Engineering)
Human breath carries diverse components of diseases such as asthma, lung cancer, type 1 diabetes mellitus, and halitosis. Thus, it is possible to analyze exhaled breath very rapidly with a simple analyzing process and it can detect trace changes in exhaled breath components, which trigger diseases.
The research team developed highly sensitive and selective chemical gas sensors that can detect specific disease, using protein-encapsulated nanocatalysts. They can diagnose certain diseases by analyzing human exhaled breath. This technology enables the early monitoring of various diseases through pattern recognition of biomarker gases associated with the diseases in human exhalation.
The established sensing libraries can detect biomarker species with high sensitivity and selectivity. The team hopes that the new and innovative breath gas analysis platform will be very helpful for reducing medical expenditures and the continuous monitoring of physical conditions.
# Detection of environmental toxic gases, monitoring of body health condition
Figure (a) Mobile device integrated with nanofiber based MEMS sensorsFigure (b) Exhaled breath pattern recognition: principle component analysis for the accurate detection of acetone, hydrogen sulfide, and toluene gases
▶ Technology for a Cancer Cure Using Big Data and Simulating Biological Network By Professor Kwang-Hyun Cho (Department of Bio and Brain Engineering)
The complex and heterogeneous nature of cancer, which results in highly variable drug responses, is a major obstacle in curing cancer. Previous methods to predict drug responses mostly focus on the static analysis of genome-wide alternations, resulting in a limitation for the understanding of cancer heterogeneity and its variable responses.
The research team used a method to integrate cancer genomics data with the dynamics of biological networks for drug response prediction and to design of effective drug combination. It provides a computational framework for evaluating drug efficacies and synergistic effects by combining the attractor landscape analysis of a biological network with the genomic alteration profiles of cancer cells.
This technology can reduce the cost of drug development by predicting drug responses and help selecting more effective new drug targets in consideration of the overall cellular response landscape. It can also provide comprehensive insight into the mechanistic origin of variable drug responses. The patent technology can be applicable to designing more effective and cancer-specific combination therapies.
# Development of targeted anticancer drugs, genetic testing
Figure (a) The computational prediction of drug responses using attractor landscape analysis of network dynamics
▶ Highly Stretchable, Wearable Strain SensorBy Professor O Ok Park (Department of Chemical and Biomolecular Engineering)
Conventional materials for strain sensor are metals or semiconductors, but these materials show a limited range of strain. To improve the stretchability of conventional materials, several projects have been done using novel materials with a high aspect ratio; nevertheless, these projects encountered problems, including complex and expensive processes, poor scalable features, and low controllability of the sensitivity in the manufacturing step.
The research team used a layer-by-layer assembly technique to control the sensitivity of the sensor in a facile and inexpensive method. By using stretchable yarn as a substrate, the graphene strain sensor gained more stretchability.
Through the newly-patented technology, the graphene strain sensor can be fabricated using an all-solution process; therefore, the sensitivity of the sensor can be easily controlled with a repetitive cycle of the coating process. The size of this sensor can be controlled as well, because it depends only on the size of coated substrate.
# Wearable strain sensor, planar strain sensor
Figure (a) Nylon-covered rubber yarn showing linear relationship between the applied strain load and its resistance change
Figure (b) Wool yarn showing an inverse relation of resistance with the applied strain load
▶ Chip & Flash Memory Data Security DeviceBy Professor Yang-Kyu Choi (School of Electrical Engineering)
Using software-based security methods can lead to having problems related to the backtracking of a security function through reverse engineering, the replication of an input value, and the forgery and modification of software. These problems should not be neglected, especially as people are increasingly recognizing the importance of personal information.
To meet the growing demands for new security methods for constructing a more perfect security system, the research team developed a hardware-based security device as well as methods for a higher level of security in the era of IoTs. The principles of the technologies are based on nanotechnology, such as mechanical deformation in a nanowire, electrical degradation in a field-effect transistor (FET), and thermal data erasing stored in the charge trap layer in flash memory. Hence, the security states are extremely safe, compared with software-based security methods and cannot be reverse-engineered by unauthorized users.
This patented technology can be used to improve the security level of logic circuits and flash memory against unauthorized users.
# Financial businesses, the defense industry, private electronics including smartphones, tablets and PCs, electronics for missions in extreme environments
Figure (a) Application for a high level of security in a logic circuit
▶ A Bio-Healthcare Device for Neuroimaging
By Professor Hyeonmin Bae (School of Electrical Engineering)There are no portable brain imaging devices and, as a result, brain diseases are often diagnosed after irreversible symptoms appeared. This can also be linked to an increase in social expenditures as a society ages.
A near-infrared spectroscopy neuroimaging device for functional brain imaging, NIRSIT, utilizes light to detect hemodynamic changes in cerebral blood flow and visualizes brain activation regions in the prefrontal area of the brain in real time.
Unlike any other existing brain imaging devices (i.e. fMRI and conventional fNIRS), NIRSIT has improved its spatial resolution while maintaining complete portability.
Furthermore, NIRSIT is probably the one and only portable and wireless NIRS device, designed to be used for brain research and clinical purposes. A software application allows the raw data extracted from the hemodynamic changes in the brain to be shown in real time on a tablet wirelessly connected to NIRSIT.
Thanks to its easy-to-use features and user-friendly design, both in hardware and in software, NIRSIT will surely set a new paradigm in the brain research and healthcare fields.
# Concussion analysis, wearable stroke monitoring, CPR monitoring, Alzheimer’s disease, neuro rehabilitation, determination of brain death
Figure (a) Image of NIRSIT, Figure (b) Neuroimaging using NIRSIT
▶ Technology for Virtual Creatures with Digitally-Emotional DNA of UsersBy Professor Jong-Hwan Kim (School of Electrical Engineering)
Currently, a large number of IT companies around the world are trying to develop a system that can offer active and emotional services and the interface method is one of the most important issues.
Although most of the existing software agents are equipped with virtual faces and voices, they do not possess a personality similar to humans. Having various personalities, like human beings, can be a charming point for users, which then leads them to have higher satisfaction with the product.
Dr. Kim’s research team developed Darwin C (Digital Agent Reconstruction with Intelligence and Natural Character), a digital agent software that provides an optimized emotional service based on personal big data, such as the user’s conversations, locations, photos, music, etc., collected from smart devices.
With this technology, the digital DNAs of a user (i.e. appearance, voice, and personality DNA) is extracted from personal data stored on various smart devices. Based on the extracted digital DNA, a 3-D software agent can be formed in a smartphone, which characterizes an individual that the user hopes to meet, such as parents, spouse, grandchild, or a celebrity.
The software agents will be expanded from Android devices to home appliances. The team expected that this technology can help customers who want to understand more about a friend or form and maintain interpersonal relations.
# Entertainment, hardware robots for education, healthcare curing depression and loneliness
Figure (a) Overview of the DarwinC technology, Figure (b) Structure of digital DNA
▶ Laser-Integrated Precision Metrological System Technology for Smart Factories By Professor Seung-woo Kim (Department of Mechanical Engineering)
In optical distance metrology, the time-of-flight method of using light pulses permits measuring distances over extensive ranges. However, the measurement precision reaches just a few tens of millimeters at most, mainly because the responsivity of the photodetectors available today is limited to the picosecond range. In addition, one device can measure only one target. For these reasons, a novel technology was devised to overcome the traditional limits of time-of-flight measurement.
This patented technology uses a highly precise, laser-integrated distance measurement system for diagnosing large machines and smart factories. This technology was devised to handle the status (e.g. position, 3-D coordinate, and thermal deformation) of multiple targets simultaneously. It is called the multi-target distance meter (MDM) and was constructed by combining a nonlinear optical crystal with a pair of femtosecond lasers.
This technology is able to measure the distances to multiple targets with a single piece of equipment, and it can easily extend the number of targets by just adding beam-splitting devices. Not only does the technology help by reducing cost and complexity, it also enables real-time quality control in the manufacturing industry.
# Real-time on-axis position inspection of a multiple-lens assembly, long-term thermal displacement monitoring of a large, precise machine, 3-D motion control of a mobile vehicle
Figure (a) Conceptual image of smart factory monitoring using laser-integrated precision metrological system technology
▶ SLAM Technology for Autonomous Robot Navigation in a Dynamic Indoor/Outdoor EnvironmentBy Professor Hyun Myung (Department of Civil & Environmental Engineering)
Dr. Myung’s research team developed SLAM (Simultaneous Localization and Mapping) technology for autonomous robot navigation in dynamic indoor/outdoor environments. Two methods were applied to this technology: a hierarchical graph structure-based 3-D high resolution map building method using a low-cost 2D laser scanner and a magnetic field-based localization method for feature-poor environments.
Existing technology required expensive sensors for outdoor environment. The localization and mapping technique were also not very accurate, especially in dynamic environments. The team wanted to provide robust SLAM in low and high dynamic object environments using the fusion of low-cost sensors, such as magnetics, 2-D LiDAR, and camera sensors.
Through this technology, the accuracy of localization and mapping could be increased to within 10cm, using low-cost sensors. Also, it facilitates localization and mapping even in feature-poor environments.
# Autonomous robot navigation in warehouses, autonomous navigation of self-driving cars, autonomous navigation of AGVs (Automated Guided Vehicles) in smart factories
Figure (a) Built outdoor 3-D mappring using a mobile robot with tilted 2-D LiDAR sensor, Figure (b) Mobile robot system for GPS-less mappring
▶ Technology for Optimizing 5G Beamforming ICBy Songcheol Hong (School of Electrical Engineering)
Dr. Hong’s team introduced a new structure for low-power, subminiature, and highly-linear beamforming IC technology. The patent used in this technology reduced the chip size and the direct current (DC) power dissipations drastically, allowing it to make mmWave beamforming antennas.
Beam-forming technology has emerged as an important area in the field of 5G communications and radar systems. It facilitates communication and signal detection with very low RF power.
The patents can be applied to 5G communication beam-forming ICs and antenna modules in mobile terminals, base stations and terminals in the automotive field. Moreover, they can be used in various mmWave radar systems for automobiles, drones, human computer interfaces, and indoor positioning.
# 5G V2X, IoTs, virtual reality
Figure (a) Active phased array system
▶ Beam Division Multiple Access TechnologyBy Professor Dong Ho Cho (School of Electrical Engineering)
Using a 5G network, a communication infrastructure for supporting high-speed, real-time services requires new technologies that enable 4x4 MIMO transmissions within beam-based wireless systems in a new frequency band and improves spectral efficiency more than ten times compared to LTE in domestic and overseas mobile communication carriers and related industries.
P2BDMA, a pattern or polarization beam division multiple access technology, is a core technology for addressing this demand for 5G networks as it enables 4x4 MIMO transmissions in mmWave frequency bands by utilizing the pattern polarization characteristic of radio waves.
The research team upgraded BDMA technology in which the same frequency resource is reused in more than two spaces by using beamforming. This technology increases the degree of freedom (DOF) of wireless communication channels, and thereby improves the achievable data transmission rate by employing multiple pattern/polarization antennas in the conventional BDMA system. The P2BDMA technique has the advantage of eliminating the frequency shortage problem and increasing the transmission speed while using the wide frequency band in a more efficient manner.
The team expects that this technology will alleviate the frequency shortage problem and CAPEX/OPEX of domestic mobile telecommunication companies, support an increase in sales for related equipment makers to make it internationally competitive, and further play a central role in providing high-speed transmission rates to a large number of IoT devices in the future IoT era.
# Autonomous vehicle, communication infrastructure, mobile access system
Figure (a) Concept of P2BDMA technology
2017.08.30 View 16008 -
KAIST Develops New Technique for Chiral Activity in Molecules
Professor Hyunwoo Kim of the Chemistry Department and his research team have developed a technique that can easily analyze the optical activity of charged compounds by using nuclear magnetic resonance (NMR) spectroscopy. The research finding entitled “H NMR Chiral Analysis of Charged Molecules via Ion Pairing with Aluminum Complexes” was published online in the October 19th issue of The Journal of the American Chemical Society.
The technique relies on observation of the behavior of optical isomers. Molecules with the same composition that are mirror images of each other are optical isomers. For example, the building blocks of all living organisms, amino acids, are a single optical isomer. In our bodies, optical isomers bring different physiological changes due to their distinct optical activities. Therefore, controlling and analyzing the optical activities are critical when developing a new drug.
High-performance liquid chromatography (HPLC) is the de facto standard of analyzing the optical activity of a compound. However, HPLC is very expensive that many laboratories can’t afford to have. In addition, with the machine, one analysis may take 30 minutes to one hour to complete. It lacks in signal sensitivity and chemical decomposition, and the application is limited to nonpolar compounds.
Usually adopted in analyzing the structure of a chemical compound, NMR spectroscopy requires only one to five minutes per single analysis. Since it is essential for analyzing the molecular structure, many chemistry labs have NMR equipment. However, until this technique was invented, no other research team had reported an effective way of using the NMR spectroscopy to decompose the signal of chiral activity of a compound.
The research team uses negatively-charged metal compounds in NMR spectroscopy. The technique employs negatively-charged metal compounds which bond ionically to positively- and negatively-charged optical compounds. As a result, the NMR spectroscopy can distinguish the signal from chiral activity. Not only can it analyze various chemicals without structural constraints, but it can also be used for both nonpolar and polar solvents.
As many compounds for new drugs have functional groups, which can be charged, this analysis method can be directly employed in the development process of drugs. Professor Kim said, “A revolutionary analysis method has been developed using simple chemical principles. I hope that our method will be applied to the development of new medicine.”
This research was sponsored by the Center for Nanomaterials and Chemical Reactions at the Institute for Basic Science and the Supercomputing Research Center of KAIST.
Picture 1: Separations of NMR Signals of Chemicals due to Interaction with Metal Compounds
Picture 2: Separations of NMR Signals in Different Chemicals
2015.11.20 View 11917 -
Mystery in Membrane Traffic How NSF Disassembles Single SNAR Complex Solved
KAIST researchers discovered that the protein N-ethylmaleimide-sensitive factor (NSF) unravels a single SNARE complex using one round ATP turnover by tearing the complex with a single burst, contradicting a previous theory that it unwinds in a processive manner.
In 2013, James E. Rothman, Randy W. Schekman, and Thomas C. Südhof won the Nobel Prize in Physiology or Medicine for their discoveries of molecular machineries for vesicle trafficking, a major transport system in cells for maintaining cellular processes. Vesicle traffic acts as a kind of “home-delivery service” in cells. Vesicles package and deliver materials such as proteins and hormones from one cell organelle to another. Then it releases its contents by fusing with the target organelle’s membrane. One example of vesicle traffic is in neuronal communications, where neurotransmitters are released from a neuron. Some of the key proteins for vesicle traffic discovered by the Nobel Prize winners were N-ethylmaleimide-sensitive factor (NSF), alpha-soluble NSF attachment protein (α-SNAP), and soluble SNAP receptors (SNAREs).
SNARE proteins are known as the minimal machinery for membrane fusion. To induce membrane fusion, the proteins combine to form a SNARE complex in a four helical bundle, and NSF and α-SNAP disassemble the SNARE complex for reuse. In particular, NSF can bind an energy source molecule, adenosine triphosphate (ATP), and the ATP-bound NSF develops internal tension via cleavage of ATP. This process is used to exert great force on SNARE complexes, eventually pulling them apart. However, although about 30 years have passed since the Nobel Prize winners’ discovery, how NSF/α-SNAP disassembled the SNARE complex remained a mystery to scientists due to a lack in methodology.
In a recent issue of Science, published on March 27, 2015, a research team, led by Tae-Young Yoon of the Department of Physics at the Korea Advanced Institute of Science and Technology (KAIST) and Reinhard Jahn of the Department of Neurobiology of the Max-Planck-Institute for Biophysical Chemistry, reports that NSF/α-SNAP disassemble a single SNARE complex using various single-molecule biophysical methods that allow them to monitor and manipulate individual protein complexes.
“We have learned that NSF releases energy in a burst within 20 milliseconds to “tear” the SNARE complex apart in a one-step global unfolding reaction, which is immediately followed by the release of SNARE proteins,” said Yoon.
Previously, it was believed that NSF disassembled a SNARE complex by unwinding it in a processive manner. Also, largely unexplained was how many cycles of ATP hydrolysis were required and how these cycles were connected to the disassembly of the SNARE complex.
Yoon added, “From our research, we found that NSF requires hydrolysis of ATPs that were already bound before it attached to the SNAREs—which means that only one round of an ATP turnover is sufficient for SNARE complex disassembly. Moreover, this is possible because NSF pulls a SNARE complex apart by building up the energy from individual ATPs and releasing it at once, yielding a “spring-loaded” mechanism.”
NSF is a member of the ATPases associated with various cellular activities family (AAA+ ATPase), which is essential for many cellular functions such as DNA replication and protein degradation, membrane fusion, microtubule severing, peroxisome biogenesis, signal transduction, and the regulation of gene expression. This research has added valuable new insights and hints for studying AAA+ ATPase proteins, which are crucial for various living beings.
The title of the research paper is “Spring-loaded unraveling of a single SNARE complex by NSF in one round of ATP turnover.” (DOI: 10.1126/science.aaa5267)
Youtube Link: https://www.youtube.com/watch?v=FqTSYHtyHWE&feature=youtu.be
Picture 1. Working model of how NSF/α-SNAP disassemble a single SNARE complex
Picture 2. After neurotransmitter release, NSF disassembles a single SNARE complex using a single round of ATP turnover in a single burst reaction.
2015.03.28 View 11039 -
High Resolution 3D Blood Vessel Endoscope System Developed
Professor Wangyeol Oh of KAIST’s Mechanical Engineering Department has succeeded in developing an optical imaging endoscope system that employs an imaging velocity, which is up to 3.5 times faster than the previous systems. Furthermore, he has utilized this endoscope to acquire the world’s first high-resolution 3D images of the insides of in vivo blood vessel.
Professor Oh’s work is Korea’s first development of blood vessel endoscope system, possessing an imaging speed, resolution, imaging quality, and image-capture area. The system can also simultaneously perform a functional imaging, such as polarized imaging, which is advantageous for identifying the vulnerability of the blood vessel walls.
The Endoscopic Optical Coherence Tomography (OCT) System provides the highest resolution that is used to diagnose cardiovascular diseases, represented mainly by myocardial infarction.
However, the previous system was not fast enough to take images inside of the vessels, and therefore it was often impossible to accurately identify and analyze the vessel condition. To achieve an in vivo blood vessel optical imaging in clinical trials, the endoscope needed to be inserted, after which a clear liquid flows instantly, and pictures can be taken in only a few seconds.
The KAIST research team proposed a solution for such problem by developing a high-speed, high-resolution optical tomographic imaging system, a flexible endoscope with a diameter of 0.8 mm, as well as a device that can scan the imaging light within the blood vessels at high speed. Then, these devices were combined to visualize the internal structure of the vessel wall.
Using the developed system, the researchers were able to obtain high-resolution images of about 7 cm blood vessels of a rabbit’s aorta, which is similar size to human’s coronary arteries. The tomography scan took only 5.8 seconds, at a speed of 350 scans per second in all three directions with a resolution of 10~35㎛.
If the images are taken every 200 ㎛, like the currently available commercial vascular imaging endoscopes, a 7cm length vessel can be imaged in only one second.
Professor Wangyeol Oh said, “Our newly developed blood vessel endoscope system was tested by imaging a live animal’s blood vessels, which is similar to human blood vessels. The result was very successful.”
“Collaborating closely with hospitals, we are preparing to produce the imaging of an animal’s coronary arteries, which is similar in size to the human heart,” commented Professor Oh on the future clinical application and commercialization of the endoscope system. He added, “After such procedures, the technique can be applied in clinical patients within a few years.”
Professor Oh’s research was supported by the National Research Foundation of Korea and the Global Frontier Project by the Korean government. The research results were published in the 2014 January’s edition of Biomedical Optics Express.
Figure 1: End portion of optical endoscope (upper left)
Figure 2: High-speed optical scanning unit of the endoscope (top right)
Figure 3: High-resolution images of the inside of in vivo animal blood vessels (in the direction of vascular circumference and length)
Figure 4: High-resolution images of the inside of in vivo animal blood vessels (in the direction of the vein depth)
2014.03.25 View 11886 -
Green Technology for Data Centers: Ultra-low Power 100 Gbps Ethernet Integrated Circuit Developed
A new integrated circuit (IC), consuming only 0.75W of electricity, will reduce the power usage of data chips installed at data centers by one-third.
Each day, billions of people surf the Internet for information, entertainment, and educational content. The Internet contains an immeasurable amount of information and knowledge generated every minute all around the world that is readily available to everyone with a click of a computer mouse. The real magic of the Internet, however, lies in data centers, where hundreds of billions of data are stored and distributed to designated users around the clock.
Today, almost every business or organization either has its own data centers or outsources data center services to a third party. These centers house highly specialized equipment responsible for the support of computers, networks, data storage, and business security. Accordingly, the operational cost of data centers is tremendous because they consume a large amount of electricity.
Data centers can consume up to 100 times more energy than a standard office building. Data center energy consumption doubled from 2000 to 2006, reaching more than 60 billion kilowatt hours per year. If the current usage and technology trends continue, the energy consumption of data centers in the US will reach 8% of the country’s total electric power consumption by 2020.
A research team at the Korea Advanced Institute of Science and Technology (KAIST) and Terasquare, Inc. (
http://www.terasquare.co.kr
), a spin-off company of the university,
developed an extremely low-powered integrated circuit for Ethernet that consumes less than 0.75W of electricity but is able to send and receive data at the high speed of 100 gigabits per second (Gbps). The research team, headed by Hyeon-Min Bae, assistant professor of electrical engineering at KAIST, claims that the new microchip uses only one-third of the electricity consumed by the currently installed chips at data centers, thereby helping the centers to save energy.
Integrated circuits are embedded on communication modules that are inserted into a line card. Data centers have numerous line cards to build a network including routers and switches. Currently, 8W ICs are the most common in the market, and they consume a lot of energy and require the largest modules (112 cm
2
of CFP), decreasing the port density of line cards and, thus, limiting the amount of data transmission.
The ultra-low-power-circuit, 100-gigabit, full-transceiver CDR, is the world’s first solution that can be loaded to the smallest communication modules (20 cm
2
of CFP4 or 16 cm
2
of
QSFP28), the next-generation chips for data centers. Compared with other chip producers, the 100 Gbps CDR is a greener version of the technology that improves the energy efficiency of data centers while maintaining the high speed of data transmission.
Professor Hyeon-Min Bae said, “When we demonstrate our chip in September of this year at one of the leading companies that manufacture optical communication components and systems, they said that our product is two years ahead of those of our competitors. We plan to produce the chip from 2014 and expect that it will lead the 100 Gbps Ethernet IC market, which is expected to grow to USD 1 billion by 2017.”
The commercial model of the IC was first introduced at the 39
th
European Conference and Exhibition on Optical Communication (ECOC), the largest optical communication forum for new results and developments in Europe, held from September 22-26 at ExCeL London, an international exhibition and convention center.
Professor Bae added, “We received positive responses to our ultra-low-power 100-Gbps Ethernet IC at the ECOC. The chip will be used not only for a particular industry but also for many of next-generation, super-high-speed information communications technologies, such as high-speed USB, high-definition multimedia interface (HDMI), and TV interface.”
Before joining KAIST, Hyeon-Min Bae worked for many years at Finisar as a researcher who designed and developed the world’s first super-high-speed circuit, the 100 Gbps Ethernet IC.
2013.11.25 View 9755 -
KAIST unveils foldable micro electric car, Armadillo-T
The small and light electric car completely folds in half when parking, making it a perfect fit for public or private transportation in an urban environment.
Looking for a parking space for hours at a busy shopping mall or being stuck on roads jammed with cars releasing large amounts of carbon dioxide are all-too-familiar scenes for city dwellers.
A group of researchers at the Korea Advanced Institute of Science and Technology (KAIST) recently developed a possible solution to such problems: a foldable, compact electric vehicle that can be utilized either as a personal car or part of the public transit system to connect major transportation routes within a city.
In-Soo Suh, associate professor of the Graduate School for Green Transportation at KAIST, and his research team introduced a prototype micro electric car called "Armadillo-T," whose design is based on a native animal of South America, the armadillo, a placental mammal with a leathery armor shell.
The research team imitated the animal"s distinctive protection characteristic of rolling up into a ball when facing with threat from predators. Just as armadillos hide themselves inside the shell, Armadillo-T tucks its rear body away, shrinking its original size of 2.8 meters (110 inches) down to almost half, 1.65 meters (65 inches), when folding.
Armadillo-T is a four-wheel-drive, all-electric car with two seats and four in-wheel motors. Since the motors are installed inside the wheels, and the 13.6 kWh capacity of lithium-ion battery pack is housed on the front side, the battery and motors do not have to change their positions when the car folds. This not only optimizes the energy efficiency but also provides stability and ample room to drivers and passengers.
Once folded, the small and light (weighs 450 kg) electric vehicle takes up only one-third of a 5-meter parking space, the standard parking size in Korea, allowing three of its kind to be parked. With a smartphone-interfaced remote control on the wheels, the vehicle can turn 360 degrees, enhancing drivers" convenience to park the car, even in an odd space in a parking lot, the corner of a building, for example.
Professor In-Soo Suh said, "I expect that people living in cities will eventually shift their preferences from bulky, petro-engine cars to smaller and lighter electric cars. Armadillo-T can be one of the alternatives city drivers can opt for. Particularly, this car is ideal for urban travels, including car-sharing and transit transfer, to offer major transportation links in a city. In addition to the urban application, local near-distance travels such as tourist zones or large buildings can be another example of application."
The concept car has loads of smart features on board, too: the cameras installed inside the car eliminate the need for side mirrors and increase the driver"s ability to see the car"s right and left side, thereby reducing blind spots. With a smartphone, the driver can control Armadillo-T and enable remote folding control. The car has a maximum speed of 60 km/h, and with a ten-minute fast charge, it can run up to 100 km.
Professor Suh explained that the concept of Armadillo-T was originally initiated in 2011 as he focused his research interest on the sub-A segment of personal mobility vehicles (PMVs), which are smaller and lighter than the current compact cars, as a new personalized transport mode.
"In coming years, we will see more mega-size cities established and face more serious environmental problems. Throughout the world, the aging population is rapidly growing as well. To cope with climate, energy, and limited petroleum resources, we really need to think outside the box, once again, to find more convenient and eco-friendly transportation, just as the Ford Model T did in the early 1920s. A further level of R&D, technical standards, and regulatory reviews are required to have these types of micro vehicles or PMVs on the market through test-bed evaluations, but we believe that Armadillo-T is an icon toward the future transport system with technology innovation."
The research project has been supported by the Korean government, the Ministry of Land, Infrastructure and Transport and the Korea Agency for Infrastructure Technology Advancement, since December 2012.Youtube Link: http://www.youtube.com/watch?v=8DoZH7Y-sR0
2013.08.21 View 15601 -
Prof. Song Chong received the IEEE William R. Bennett Prize Paper Award
The IEEE (Institute of Electrical and Electronics Engineers) Communications Society (ComSoc), a renowned global network of professionals with a common interest in advancing communications technologies, has announced the winner of the 2013 William R. Bennett Prize in the field of communications networking. The prize was given to a Korean research team led by Song Chong, Professor of Electrical Engineering at KAIST and Injong Rhee, Professor of Computer Science at North Carolina State University. In addition, Dr. Minsu Shin, Dr. Seongik Hong, and Dr. Seong Joon Kim of Samsung Electronics Co., Ltd. as well as Professor Kyunghan Lee from Ulsan National Institute of Science and Technology were recognized for their contribution.
The William R. Bennett Prize for communications networking has been awarded each year since 1994 in recognition of the best paper published in any journal financially sponsored or co-sponsored by ComSoc in the previous three calendar years. Only one paper per year is selected based on its quality, originality, scientific citation index, and peer reviews. Among the previous award winners are Robert Gallager of MIT, and Steven Low of the California Institute of Technology, and Kang G. Shin of the University of Michigan.
The Korean research team’s paper, On the Levy-Walk Nature of Human Mobility, was published in the June 2011 issue of IEEE/ACM Transactions on Networking, a bimonthly journal co-sponsored by the IEEE ComSoc, the IEEE Computer Society, and the Association for Computing Machinery (ACM) with its Special Interest Group on Data Communications (SIGCOMM).
In the paper, the research team proposed a new statistical model to effectively analyze the pattern of individual human mobility in daily life. The team handed out GPS (global positioning system) devices to 100 participants residing in five different university campuses in Korea and the US and collected data on their movements for 226 days. The mobility pattern obtained from the experiment predicted accurately how the participants actually moved around during their routines. Since publication, the paper has been cited by other papers approximately 350 times.
The team’s research results will apply to many fields such as the prevention and control of epidemics, the design of efficient communications networks, and the development of urban and transportation system.
The research team received the award on June 10th at the 2013 IEEE International Conference on Communications (ICC) held in Budapest, Hungary, from June 9-13, 2013.
Professor Song Chong
2013.07.06 View 14156 -
KAIST develops a low-power 60 GHz radio frequency chip for mobile devices
As the capacity of handheld devices increases to accommodate a greater number of functions, these devices have more memory, larger display screens, and the ability to play higher definition video files. If the users of mobile devices, including smartphones, tablet PCs, and notebooks, want to share or transfer data on one device with that of another device, a great deal of time and effort are needed.
As a possible method for the speedy transmission of large data, researchers are studying the adoption of gigabits per second (Gbps) wireless communications operating over the 60 gigahertz (GHz) frequency band. Some commercial approaches have been introduced for full-HD video streaming from a fixed source to a display by using the 60 GHz band. But mobile applications have not been developed yet because the 60 GHz radio frequency (RF) circuit consumes hundreds of milliwatts (mW) of DC power.
Professor Chul Soon Park from the Department of Electrical Engineering at the Korea Advanced Institute of Science and Technology (KAIST) and his research team recently developed a low-power version of the 60 GHz radio frequency integrated circuit (RFIC). Inside the circuit are an energy-efficient modulator performing amplification as well as modulation and a sensitivity-improved receiver employing a gain boosting demodulator.
The research team said that their RFIC draws as little as 67 mW of power in the 60 GHz frequency band, consuming 31mW to send and 36mW to receive large volumes of data. RFIC is also small enough to be mounted on smartphones or notebooks, requiring only one chip (its width, length, and height are about 1 mm) and one antenna (4x5x1 mm3) for sending and receiving data with an integrated switch.
Professor Park, Director of the Intelligent Radio Engineering Center at KAIST, gave an upbeat assessment of the potential of RFIC for future applications. What we have developed is a low-power 60-GHz RF chip with a transmission speed of 10.7 gigabits per second. In tests, we were able to stream uncompressed full-HD videos from a smartphone or notebook to a display without a cable connection (Youtube Link: http://www.youtube.com/watch?v=6PVSLBhMymc). Our chip can be installed on mobile devices or even on cameras so that the devices are virtually connected to other devices and able to exchange large data with each other."
2013.04.02 View 8965 -
New wireless charging device developed
The On-line Electric Vehicle (OLEV) developed by KAIST has made a step towards commercialization with the development of a more economic wireless charging device.
Professor Chun-Taek Rim from the Department of Nuclear and Quantum Engineering at KAIST has developed a new I-shaped wireless charging device that differs from the pre-existing rail-type electricity feeder. This device can be modularly produced and requires relatively less construction, significantly reducing the cost of implementation.
The KAIST OLEV is a new concept electric car that has a special electricity collecting device underneath it. The car’s battery is charged by magnetic fields produced from electric lines buried 15cm underneath the road. The vehicle was first tested in 2009, making it the first wireless electric car in the world. OLEV can be charged during stoppage time between traffic lights and receives real-time power when running. OLEV is currently in operation at the KAIST Munji Campus in Daejeon and is also being exhibited at the Yeosu Expo and Seoul Grand Park.
The device itself has a charging capacity of 15kW, and the electricity is supplied through an electricity feeder with a width of 80cm with a space interval of 20cm. Despite being hailed as a technological breakthrough and revolutionary concept, KAIST OLEV has been criticized for problems in commercialization, due to the difficulties in installing wires beneath existing roads, which costs a considerable amount of money.
The new I-shaped wireless charging device reduces the width of the electricity feeder by 10cm, a mere one-eighth of the size of the previous version, and greatly increases the charging power to 25kW. Furthermore, the left and right permissible space of automobiles has increased to 24cm and the magnetic field complies with the international design guidelines, making the OLEV safe for the human body.
The reduction of the width has made the mass production of modules possible, making the installation of KAIST OLEV more economical and marketable. Professor Rim emphasized that compared with the existing rail-type electricity feeder, the new technology will need only one-tenth of the construction time and 80% of the cost, significantly improving OLEV’s constructability and workability.
The research was published in the IEEE Transactions on Power Electronics last December, and Professor Rim was invited to talk at the Conference on Electric Roads & Vehicles, which was held in February in the United States, about the new technology.
2012.07.06 View 12168
-
KAIST College of Business ranks no.1 in Asia for executive education
KAIST College of Business ranked 28th in the world and 1st in Asia in the UK Financial Times (FT) 2012 Executive Education open ranking, making it the only school in Korea to be included.
The FT ranking selects the world’s top 65 business graduate schools based on executive education course design, teaching methods & materials, faculty, new skills & learning, quality of participants, and several other criteria. Last year, the KAIST executive education program ranked 29th in the world and 2nd in Asia. This year, it surpassed China’s CEIBS to rank 1st in Asia and has now been included in the ranking for three consecutive years.
Looking at the individual criteria, KAIST ranked highly in course preparation (11th), international location (11th), facilities (12th), and follow-up (5th) and saw increases in aims achieved (31st) and course design (29th).
KAIST attributed its success to the differentiation and specialization of education courses based on position, industry, and enterprise. KAIST College of Business operates an integrative course that fuses business management with science & technology, information media, medicine and innovation. The school runs both a chief and junior executive program to cater to different positional needs and provides specialized lectures that consider a company’s industry and size.
The ‘international location’ criteria saw a huge leap from 23rd to 11th due to the use of both long term and short term overseas exchange programs. The ‘Global Leader’ course created in 2011 is taught only in English and allows students to study abroad in a partner school in the second semester. The college’s knowhow in the MBA program also achieved recognition with high rankings in new skills & learning (18th) as well as in teaching methods & materials (24th).
College of Business President Lee Byung Tae said that the school’s success was achieved through a specialized curriculum that considers the market and explained that the ranking reflects the school’s competitiveness. He also said that KAIST will continue to provide the best educational services appropriate for KAIST’s outstanding reputation.
In the overall ranking, Swiss IMD was ranked number 1, followed by the Harvard Business School. In Asia, China’s CEIBS (29th), Singapore’s Aalto University (42nd), and the National University of Singapore Business School (64th) followed suit.
2012.05.17 View 10237