Engineering
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Interesting research results were published on the use of Twitter.
The number of “followers” on your Twitter account does not necessarily mean that “Your opinions matter much” to other people.
A KAIST graduate researcher, Mi-Young Cha, joined an interesting project that studies the influence of a popular social media, Twitter. Most of Twitter users today consider the number of followers as a measurement of their influence on the social sphere. According to the research paper, however, this connection does not seem to standing together. For details, please click the link below for an article published by the New York Times.
Dr. Cha received all of her post secondary education degrees in Computer Science, including her Ph.D. in 2008, from KAIST. Since 2008 till now, she has been a post doctoral researcher at Max Planck Institute for Software Systems (MPI-SWS) based in Germany.
[New York Times Article, March 19, 2010]
http://www.nytimes.com/external/readwriteweb/2010/03/19/19readwriteweb-the-million-follower-fallacy-audience-size-d-3203.html
2010.04.05 View 12189 -
New drug targeting method for microbial pathogens developed using in silico cell
A ripple effect is expected on the new antibacterial discovery using “in silico” cells
Featured as a journal cover paper of Molecular BioSystems
A research team of Distinguished Professor Sang Yup Lee at KAIST recently constructed an in silico cell of a microbial pathogen that is resistant to antibiotics and developed a new drug targeting method that could effectively disrupt the pathogen"s growth using the in silico cell.
Hyun Uk Kim, a graduate research assistant at the Department of Chemical and Biomolecular Engineering, KAIST, conducted this study as a part of his thesis research, and the study was featured as a journal cover paper in the February issue of Molecular BioSystems this year, published by The Royal Society of Chemistry based in Europe.
It was relatively easy to treat infectious microbes using antibiotics in the past. However, the overdose of antibiotics has caused pathogens to increase their resistance to various antibiotics, and it has become more difficult to cure infectious diseases these days.
A representative microbial pathogen is Acinetobacter baumannaii. Originally isolated from soils and water, this microorganism did not have resistance to antibiotics, and hence it was easy to eradicate them if infected. However, within a decade, this miroorganism has transformed into a dreadful super-bacterium resistant to antibiotics and caused many casualties among the U.S. and French soldiers who were injured from the recent Iraqi war and infected with Acinetobacter baumannaii.
Professor Lee’s group constructed an in silico cell of this A. baumannii by computationally collecting, integrating, and analyzing the biological information of the bacterium, scattered over various databases and literatures, in order to study this organism"s genomic features and system-wide metabolic characteristics. Furthermore, they employed this in silico cell for integrative approaches, including several network analysis and analysis of essential reactions and metabolites, to predict drug targets that effectively disrupt the pathogen"s growth. Final drug targets are the ones that selectively kill pathogens without harming human body.
Here, essential reactions refer to enzymatic reactions required for normal metabolic functioning in organisms, while essential metabolites indicate chemical compounds required in the metabolism for proper functioning, and their removal brings about the effect of simultaneously disrupting their associated enzymes that interact with them.
This study attempted to predict highly reliable drug targets by systematically scanning biological components, including metabolic genes, enzymatic reactions, that constitute an in silico cell in a short period of time.
This research achievement is highly regarded as it, for the first time, systematically scanned essential metabolites for the effective drug targets using the concept of systems biology, and paved the way for a new antibacterial discovery. This study is also expected to contribute to elucidating the infectious mechanism caused by pathogens.
"Although tons of genomic information is poured in at this moment, application research that efficiently converts this preliminary information into actually useful information is still lagged behind. In this regard, this study is meaningful in that medically useful information is generated from the genomic information of Acinetobacter baumannii," says Professor Lee. "In particular, development of this organism"s in silico cell allows generation of new knowledge regarding essential genes and enzymatic reactions under specific conditions," he added.
This study was supported by the Korean Systems Biology Project of the Ministry of Education, Science and Technology, and the patent for the development of in silico cells of microbial pathogens and drug targeting methods has been filed.
[Picture 1 Cells in silico]
[Picture 2 A process of generating drug targets without harming human body while effectively disrupting the growth of a pathogen, after predicting metabolites from in silico cells]
2010.04.05 View 14609
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Photonic crystals allow the fabrication of miniaturized spectrometers
By Courtesy of Nanowerk
Photonic crystals allow the fabrication of miniaturized spectrometers
(Nanowerk Spotlight) Spectrometers are used in materials analysis by measuring the absorption of light by a surface or chemical substance. These instruments measure properties of light over a specific portion of the electromagnetic spectrum. In conventional spectrometers, a diffraction grating splits the light source into several beams with different propagation directions according to the wavelength of the light. Thus, to achieve sufficient spatial separation for intensity measurements at a small slit, a long light path – i.e., a large instrument – is required.
However, for lab-on-a-chip or microTAS (total analysis system) applications, the spectrometer must be integrated into a sub-centimeter scale device to produce a stand-alone platform. To achieve this, researchers at the Korea Advanced Institute of Science and Technology (KAIST) propose a new paradigm in which the spectrometer is based on an array of photonic crystals with different bandgaps.
"Because photonic crystals refelct light of different wavelengths selectively depending on their bandgaps, we can generate reflected light spanning the entire wavelength range for analysis at different spatial positions using patterned photonic crystals," Seung-Man Yang, Director of the National Creative Research Initiative Center for Intergrated Optofluidic Systems and Professor of the Department of Chemical & Biomolecular Engineering at KAIST, tells Nanowerk. "Therefore, when the light source impinges on the patterned photonic crytals, we can construct the spectrum using the reflection intensity profile from the constituent photonic crystals."
Photonic crystals – also known as photonic band gap material – are similar to semiconductors, only that the electrons are replaced by photons (i.e. light). By creating periodic structures out of materials with contrast in their dielectric constants, it becomes possible to guide the flow of light through the photonic crystals in a way similar to how electrons are directed through doped regions of semiconductors. The photonic band gap (that forbids propagation of a certain frequency range of light) gives rise to distinct optical phenomena and enables one to control light with amazing facility and produce effects that are impossible with conventional optics.
To demonstrate this new concept based on patterned photonic crystals, Yang and his group used non-close-packed colloidal crystals of silica particles dispersed in photocurable resin. Due to the repulsive interparticle potential, monodisperse silica particles spontaneously crystallize into non-close-packed face-centered cubic (fcc) structures at volume fractions above 0.1. Therefore, the particle volume fraction determines both the lattice constant and the bandgap position.
a) Optical image of an ETPTA film containing porous photonic crystal stripe patterns with 20 different bandgaps. b) Reflectance spectra from the 20 strips. c) Optical microscope image of the middle region with the parallel stripe pattern (denoted as white-dotted box in a). d) Cross-sectional SEM images of first, sixth, eleventh and seventeenth strips. The scale bars in a, c and d are 1 cm, 2mm and 2 µm, respectively. (reprinted with permission from Wiley-VCH Verlag)
Reporting their findings in a recent issue of Advanced Materials ("Integration of Colloidal Photonic Crystals toward Miniaturized Spectrometers"), the KAIST team has demonstrated the integration of colloidal photonic crystals with 20 different bandgaps into freestanding films (prepared by soft lithography), and their application as a spectrometer.
Yang explains that the team was able to precisely control the photonic bandgap by varying the particle size and volume fration.
"The prepared colloidal composite structures showed high physical rigidity and chemical resistivity" he says. "The composite structure is suitable for spectroscopic use due to the small full widths at half maximum (FWHMs) of the reflectance spectra, which mean that there is little overlap of the reflectance spectra of neighboring photonic crystal strips."
"On the other hand" says Yang, "porous photonic crystals showed large FWHMs and high reflectivities, which should prove useful in many practical photonic applications that require high optical performance and physical rigidity as well as simple and inexpensive preparation."
In addition to fabricating miniaturized spectrometers, which can for instance be integrated into small lab-on-a-chip devices, these integrated photonic crystals can be potentially used for tunable band reflection mirrors, optical switches, and tunable lasing cavities. Moreover, patterned photonic crystals with RGB colors are well-suited for use in reflection-mode microdisplay devices.
Yang points out that, although the spectrometric resolution can be reduced by employing the smaller bandgap interval and photonic bandwidth, there is a limitation. "Now, we are studying photonic crystals with continuous modulation of bandgap position. We expect that the photonic crystals can reduce the resolution to 0.01 nm."
By Michael Berger. Copyright 2010 Nanowerk
2010.03.17 View 13033
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[Event Notice] International Workshop on Computer Science Education and Research
2010 Asia-Africa International Workshop on Computer Science Education and Research
The Department of Computer Science at KAIST will host an international workshop on the education and research of computer science in Asia and Africa. The workshop, “2010 Asia-Africa International Workshop on Computer Science Education and Research” will be held on February 17-19, 2010 at a conference room located inside the KAIST Main Building. Deans of computer science departments from 13 different universities in Asia and Africa will attend the workshop.
At the workshop, participants will introduce their own education and research programs and discuss ways to have mutual collaborations. This is the first time for representatives from the computer science and engineering departments of leading universities in the newly developing countries—for instance, Thailand, Vietnam, Nigeria, Egypt, and Indonesia—to attend a meeting organized by institutions based in Korea. These countries have a large amount of natural resources and great potential to grow as a front runner in the information technology (IT) sector.
Professor Key-Sun Choi, Dean of Computer Science Department at KAIST, hopes that the workshop will be a place where participated universities discuss mutual cooperation and collaboration; exchange their ideas and knowledge of course management and education and research experiences; and share their vision of global leadership to advance the development of computer science and engineering.
Dean Choi mentioned that his department has also had consultations with the Korean government regarding a possible exchange program to select 10 or 20 members of faculty and students from universities in the newly developing nations for a doctoral course at KAIST. The exchange program, he said, would attract many of excellent candidates from nations with an emerging market for the IT industry to study at KAIST. The highly trained workforces who finish the KAIST doctoral program will contribute not only to their nations’ IT development but also to Korea’s.
2010.02.18 View 12476
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A Breakthrough for Cardiac Monitoring: Portable Smart Patch Makes It Possible for Real-time Observation of Heart Movement
Newly invented device makes the monitoring easier and convenient.
Professor Hoi-Jun Yoo of KAIST, Department of Electrical Engineering, said that his research team has invented a smart patch for cardiac monitoring, the first of its kind in the world. Adhesive and can be applied directly to chest in human body, the patch is embedded with a built-in high performance semiconductor integrated circuit (IC), called Healthcare IC, and with twenty five electrodes formed on the patch’s surface.
The 25-electrodes, with a capability of creating various configurations, can detect cardiac contractions and relaxations and collect electrocardiogram (ECG) signals. The Healthcare IC monitors ECG signals and sends the information to a portable data terminal like mobile phones, making it possible for a convenient, easy check up on cardiac observations.
The key technologies used for the patch are the Healthcare IC that measures cardiovascular impedance and ECG signals, and the electronic circuit board made of four layers of fabric, between which electrodes, wireless antenna, circuit board, and flexible battery are installed. With the P-FCB (Planar Fashionable Circuit Board) technology, the research team explained, electrodes and a circuit board are directly stacked into the fabric. Additionally, the Healthcare IC (size: 5mm x 5mm), which has components of electrode control unit, ECG and cardiovascular resistance detection unit, data compression unit, Static Random Access Memory (SRAM), and wireless transmitter receiver, is attached on the fabric. The Healthcare IC is operated by an ultra-low electrical power.
Like a medicated patch commonly used to relieve arthritis pains, the surface of smart patch is adhesive so that people can carry it around without much hassle. A finished product will be 15cm x 15 cm in size and 1mm high in thickness. The Healthcare IC can measure cardiovascular impedance variances with less than 0.81% distortion in 16 different configurations through differential current injectors and reconfigurable high sensitivity detection circuitry.
“The patch will be ideal for patients who suffer a chronic heart disease and need to receive a continuous care for their condition. Once commercialized, the patch will allow the patients to conduct a self-diagnosis at anytime and anywhere,” said Yan Long, a member of the research team.
There has been a continuously growing demand worldwide since 2000 for the development of technology that provides a suitable healthcare management to patients with a chronic heart disease (e.g., cardiovascular problems), but most of the technology developed today are only limited to monitoring electrical signals of heart activity. Cardiovascular monitors, commonly used at many of healthcare places nowadays, are too bulky to use and give uncomfortable feelings to patients when applied. Besides, the current monitors are connected to an electrical line for power supply, and they are unable to have a low power communication with an outdoor communication gadget, thus unavailable for wide use.
Professor Yoo gave his presentation on this new invention at an international conference, International Solid-State Circuits Conference, held on February 8-10 in San Francisco. The subject of his presentation was “A 3.9mW 25-electorde Reconfigurable Thoracic Impedance/ECG SoC with Body-Channel Transponder.”
(Picture 1) Structure of Smart Patch
(Picture 2) Smart patch when applied onto human body
(Picture 3) Data received from smart patch
(Picture 4) Healthcare IC
2010.02.17 View 13703
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Indoor Localization System for Mobile Devices Developed by KAIST Research Team
The technology will be available to smart phone users around the world through Goole Apps Store.
The wireless fidelity (WiFi)-based indoor localization can be installed on smart phones for commercialization, a technology developed by a research team at KAIST. The KAIST research team, led by Professor Dong-Soo Han, Department of Computer Science and Engineering, explained that the technology offers smart phone users, e.g., Google’s Android phone and Apple’ iPhone, a unique way to recognize their location through WiFi Open Radio Map. WiFi Open Radio Map is built with WiFi Location Fingerprint that contains wireless local area network (LAN)’s signal strength and wireless access points (AP) number, and with location information.
Through using the Map, WiFi-based indoor localization recognizes the location of smart phones and sends the location information to the phones. Since the technology uses WiFi signal information only to recognize the whereabouts of phones, it can be widely used in the future, without installing extra machines and equipment for detection, for a complicated, large indoor environment, where the Global Positioning System (GPS) is not available.
Currently, Professor Han has established WiFi Open Radio Map inside and outside of a few buildings at KAIST and developed several location based application services to perform a beta testing. He plans to open and distribute the technology to smart phone users through Google and Apple Apps Store in early 2010. Collaborations with major smart phone makers such as SK Telecom, Korea Telecom, and Samsung as well as outdoor/indoor localization manufactures and suppliers will also be sought, according to Professor Han.
Professor Han is invited to an international conference, Eighth Annual IEEE International Conference on Pervasive Computing and Communications, slated for early April 2010, in recognition of his work. At the conference, he will give a presentation on WiFi based indoor localization technology and conduct its demo version.
2010.02.10 View 10943
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KAIST Research Team Identified Promising New Source to Obtain Stem Cells
KAIST Research Team Identified Promising New Source to Obtain Stem Cells
A research team at KAIST led by Professor Gou-Young Koh, M.D. and Ph.D., of the Department of Biological Sciences, has found evidence that fat tissue, known as adipose tissue, may be a promising new source of valuable and easy-to-obtain regenerative cells called hematopoietic stem and progenitor cells (HSPCs).
HSPCs are adult stem cells that have the ability to generate and develop into many different kinds of cells. They are now used to repair damaged tissues and are being studied for their potential to treat a vast array of chronic and degenerative conditions such as leukemia. Mostly found in bone marrow but with a limited quantity, HSPCs are hard to cultivate in vitro, thus becoming an obstacle to use them for research and therapeutic purposes.
Within the adipose tissue is a special cell population known as the stromal vascular fraction (SVF), which share similar properties to those in the bone marrow. Cells in the bone marrow and SVF have the ability to differentiate into several cell types. In addition, both adipose and bone marrow offer similar environments for optimal stem cell growth and reproduction.
Given the fact that adipose and bone marrow tissues share similar properties, Dr. Koh and his team conducted a research, injecting granulocyte colony-stimulating factor (G-CSF), a growth hormone used to encourage the development of stem cells, into an adipose tissue of a mouse whose bone marrow is damaged. As a result, the team has found that the SVF derived from adipose tissue contains functional HSPCs capable of generating hematopoietic (blood-forming) cells to repair the damaged bone morrow.
The Ministry of Education, Science and Technology nominated the KAIST research as one of its sponsoring 21st Century Frontier R&D Programs. Director Dong-Wook Kim of Stem Cell Research Center (SCRS) that oversees the KAIST team expressed a possibility to use the adipose tissue as an alternative source to obtain stem cells for regeneration medicine.
Dr. Koh also said, “It’s been a well known method to extract HSPCs from the bone morrow or blood, but it’s the first time to identify adipose tissue, before considered useless, as a new possible supplier for functional and transplantable HSPCs.”
The study results have received an important recognition from the academia—the American Society of Hematology published the research as a main article in its official journal, Blood, for the February 4th, 2010 issue, which is the most citied peer-reviewed publication in the field.
2010.02.05 View 11624
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Opening Ceremony Held on February 3, 2010 for Intellectual Property Training Center
KAIST Opened Training Center for Young Entrepreneurs
Commissioner Jung-Sik Koh of Korean Intellectual Property Office (KIPO) and KAIST faculty members including Soon-Hong Jang, Vice President of Operations and Kwang-Hyung Lee, Dean of Academic Affairs Office, joined an opening ceremony held on February 3rd, 2010 to launch a training center for the next generation entrepreneurs who will lead the intellectual property (IP) industry in Korea.
The training center was built in cooperation with KIPO to educate and support young entrepreneurs and prepare them to become tomorrow’s IP business leaders like Bill Gates of Microsoft and Google’s founders, Larry Page and Sergey Brin.
Going through a vigorous selection process, a total of 101 students (51 for intermediate and 50 for advanced level) were chosen last December for an orientation program that will begin February 3rd and continue through February 5th. In addition to the training center at KAIST, KIPO supported to launch another training center at the Pohang University of Science and Technology (POSTECH), which has been up and running since January 27th, 2010.
2010.02.04 View 12487 -
Prof. Lee"s Team Succeeds in Producing Plastics Without Use of Fossil Fuels
A team of scientists led by Prof. Sang-Yup Lee of the Department of Biological Sciences at KAIST have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals, the university authorities said on Tuesday (Nov. 24).
This groundbreaking research, which may now allow for the production of environmentally conscious plastics, has been published in two papers in the journal Biotechnology and Bioengineering.
Polymers are molecules found in everyday life in the form of plastics and rubbers. The team consisted of scientists from KAIST and Korean chemical company LG Chem focused their research on polylactic acid (PLA), a bio-based polymer which holds the key to producing plastics through natural and renewable resources.
"The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process," said Lee. "The idea of producing polymers from renewable biomass has attracted much attention due to the increasing concerns of environmental problems and the limited nature of fossil resources. PLA is considered a good alternative to petroleum based plastics as it is both biodegradable and has a low toxicity to humans."
Until now PLA has been produced in a two-step fermentation and chemical process of polymerization, which is both complex and expensive. Now, through the use of a metabolically engineered strain of E.coli, the team has developed a one-stage process which produces polylactic acid and its copolymers through direct fermentation. This makes the renewable production of PLA and lactate-containing copolymers cheaper and more commercially viable.
"By developing a strategy which combines metabolic engineering and enzyme engineering, we"ve developed an efficient bio-based one-step production process for PLA and its copolymers," said Lee. "This means that a developed E. coli strain is now capable of efficiently producing unnatural polymers, through a one-step fermentation process,"
This combined approach of systems-level metabolic engineering and enzyme engineering now allows for the production of polymer and polyester based products through direct microbial fermentation of renewable resources.
"Global warming and other environmental problems are urging us to develop sustainable processes based on renewable resources," concluded Lee. "This new strategy should be generally useful for developing other engineered organisms capable of producing various unnatural polymers by direct fermentation from renewable resources".
2009.11.30 View 13868 -
Prof. Sang-Yup Lee Founding Member of Board of Editors of mBop
Prof. Sang-Yup Lee of the Department of Chemical and Biomolecular Engineering at KAIST has been appointed as one of the founding board of editors of the mBio which will be launched next year, the university reported on Friday (Nov. 20).
mBio is the American Society for Microbiology"s first all-online, open access journal which will be launched in next May. According to the mBio website, the journal"s scope "will reflect the enormity of the microbial world, a highly interconnected biosphere where microbes interact with living and non-living matter to produce outcomes that range from symbiosis to pathogenesis, energy acquisition and conversion, climate change, geologic change, food and drug production, and even animal behavioral change."
Prof. Lee, LG Chem Chair Professor, is currently the Dean of the College of Life Science and Bioengineering and director of the Center for Systems and Synthetic Biotechnology. He received his B.S. in Chemical Engineering from Seoul National Univeristy in Korea and his M.S. and Ph.D. in Chemical Engineering from Northwestern University.
As of September 2009, he has published 298 journal papers and has more than 440 patents either registered or applied. Also, he has published 47 books/book chapters, "Systems Biology and Biotechnology of Escherichia Coli" being the latest.
His research interests are systems biology and biotechnology, industrial biotechnology, metabolic engineering, synthetic biology and nanobiotechnology. In particular, he has pioneered systems metabolic engineering, which integrates systems biology with metabolic engineering, for the development of micropoganisms possessing superior properties for industrial applications.
2009.11.20 View 11597 -
Prof. Yu Wins Sidney Stein International Award
Prof. Jin Yu of the Department of Materials Science and Engineering won the Sidney J. Stein International Award at the plenary session of the International Microelectronics and Packaging Society (IMAPS) held in San Jose, the United States, on Nov. 3.
The Sidney Stein International Award recognizes an individual who is regarded as providing significant international technical and/or leadership contributions to the microelectronics packaging industry, while participating and demonstrating support of IMAPS international activities to enhance the electronics packaging profession.
The International Microelectronics And Packaging Society is the largest society dedicated to the advancement and growth of microelectronics and electronics packaging. It offers chapters around the globe, creating global networks of more than 4,000 members in the United States and an additional 4,000 members throughout Europe and Asia. Prof. Yu currently serves as the chairman of its Asia League Chapter and the Korean Microelectronics and Packaging Society.
2009.11.20 View 11438 -
Prof. Woo's Team Discovers Eco-Friendly Solid-Oxide Fuel Cell System
A KAIST research team led by Prof. Seong-Ihl Woo of the Department of Chemical & Biomolecular Engineering has found a method to use glycerol, a byproduct from the production of biodiesel, as fuel for solid oxide fuel cells (SOFC), university authorities said on Tuesday (Oct. 27).
The research finding shows that glycerol can be an environmentally sustainable fuel when it is used for operating SOFCs with internal reforming, instead of hydrogen and methane. The finding was published in the Oct. 14, 2009 online edition of ChemSusChem, a sister journal of Angewandte Chemie, the world"s leading chemistry journal.
Biodiesel is an attractive alternative energy source because of its low sulfur content and demand is growing worldwide as oil price soars. Bio-derived glycerol will not contribute to the greenhouse effect and has the potential to contribute to reducing global warming.
Currently, glycereol is used as a raw material in the cosmetic, pharmacy, food, and tobacco industries. However, its supply exceeds its demand as the volume of biodiesel production increases. The production of 1 ton of biodiesel produces 0.1 ton of glycerol. Many researchers have investigated various routes for the consumption of surplus glycerol.
The research is expected to contribute to sustainable growth by reducing the emissions of carbon dioxide and reusing generated carbon dioxide for the production of biomass. The new method enables manufacturers to use glycerol as a fuel for operating SOFC.
2009.10.28 View 12283