Korean
Uncovering the novel frictio..
Graphene, a single layer of graphite, is attracting great interest due to its remarkable electrical and mechanical properties and possible applications in emerging electronic devices. Mechanical exfoliation, however, may induce strain on the graphene layer during deposition on a substrate and can create wrinkled films and other defects. In this work, the observation of domains on an exfoliated monolayer of graphene differing in terms of their friction characteristics was undertaken. The charge transport properties of mechanically stressed graphene under mechanical stress were studied. Current mapping on a single layer of graphene prepared using the inductively-coupled plasma chemical vapor deposition technique revealed nanoscale domain boundaries. The influence of certain types of chemical modification of graphene, including fluorination, oxidation and hydrogenation, on the friction and charge transport properties was studied and a theoretical model based on changes in the local stiffness was obtained.
High-resolution EM of colloi..
In this work, we succeeded in creating a graphene liquid cell (GLC) for the real-time and in situ imagining of nanoscale processes in fluids with atomic-level resolutions using a transmission electron microscope (TEM) as a world’s first. The graphene liquid cell (GLC) is composed of two sheets of graphene sandwiched to create a sealed chamber in which a platinum growth solution is encapsulated in the form of a thin slice. Graphene is the thinnest material made out of carbon atoms. It has unique properties, such as good mechanical tensile strength, high flexibility, impermeability to small molecules, and high electrical conductivity. Graphene is an excellent material when used to hold micro- and nanoscopic objects for observation by a transmission electron microscope. It has thus far been impossible to image liquid samples in TEM under high vacuum conditions due to evaporation. However, we employed this technique to explore the mechanism of colloidal Pt nanocrystal growth at an atomic level.
World’s best super-stretchable..
Have you ever thought of electronics that can stretch like a rubber band? Rarely is it possible to find electronic materials that can stretch, but if found, they could make sci-fi fantasies a reality. Skin tattoos that can replace your mobile devices, display screens that can be folded into your pocket, suits that can serve your computational needs all become possible with the proper stretchable electronic material. Prof. Jeon’s research team created the world’s largest and most stretchable 3D nanoporous electrical conductor using their proprietary 3D nanopatterning technologies. The group boasts the capacity to produce rubber-band electronic conductors that are larger than one square inch and that can stretch far beyond typical natural limits. The secret to this technology is the ability to convert a solid elastomer into one containing highly ordered and uniform 3D nano-networks, which help distribute and deconcentrate the strain across the nanosized bridging elements used. The team demonstrated a stretchable LED system that could stretch up to 220% beyond its natural limits without compromising its electrical performance or robustness.
MoleBot: Organic user interfac..
What would it be like to have a mole living under your table, pushing objects around on the table surface? Professor Woohun Lee’s Design Media Lab attempted to confer physical transformability to rigid objects based on the concept of an organic user interface (OUI), turning a table into a new game platform known as MoleBot by integrating digital information with physical pixels. To ensure the fluid motion of the molehills produced by MoleBot, the table surface combines horizontal rigidity with vertical flexibility using 15,000 movable pins. Users can interact kinetically with this robotic creature via a joystick or through gestural commands.
Touchscreen based Ebook Navig..
- Developed a continuous page flipping and navigation method on touchscreen based e-readers - Based on a skeuomorphic design approach in which a paper book reading metaphor was applied to a touchscreen user interface (bezel-flipping/finger-bookmarking). The advantages of the touchscreen device itself were considered (e.g., the touch time, speed, pressure, gesture) and combined into an efficient page navigational interface. - A touchscreen bezel gesture recognition algorithm was developed, applied to page-flipping menu initiation, enabling minimized user input and maximizing the content area
Software-based high-speed ne..
A network intrusion detection system (NIDS) is a real-time network security monitoring system that detects or prevents various attacks on the Internet. Unfortunately, existing NIDSes are associated with either poor performance or employ expensive dedicated hardware for high-speed networks, which prevents their wider deployment. We present Kargus, a low-cost but highly scalable software-based NIDS that exploits many-core GPUs and multi-core CPUs for high-performance pattern matching with batch and parallel processing. Kargus proves for the first time that even a commodity server can achieve multi-10Gbps intrusion detection performance.
Direct visualization of larg..
The boundaries between domains in graphene strongly influence the electronic, mechanical and thermal properties of this material. However, existing tools such as atomic force microscopy, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy with 2D mapping for the visualization of domains are only effective for domains that are less than a few micrometers in size. We developed a simple method for the visualization of large graphene domains by imaging the birefringence of a graphene surface covered with nematic liquid crystals. This technique should therefore open a new direction for studies directed at the elucidation of factors that control the domains, structures and properties of graphene, which is critical to realize their potential applications.
Nitrogen-doped graphene for hi..
Supercapacitors, as a next-generation energy storage device, have drawn great attention from both industrial and academic communities due to their high-power characteristics. However, they have the drawback of a low specific capacitance (~70 F/g). In this study, using nitrogen-doped graphene (N-doped graphene) through a simple plasma treatment, we demonstrated high-performance supercapacitors whose capacitances (~280 F/g) are nearly four times larger than those of pristine graphene without sacrificing the original advantages of supercapacitors, such as their high power capability and long cycle lifetimes. Such propitious properties are attributed to the enhanced binding affinity between N-doped graphene and the electrolyte used. In addition, the supercapacitors based on N-doped graphene exhibited stable cycling performance up to >200,000 without almost no capacitance loss. Furthermore, with the flexible properties of N-doped graphene, wearable supercapacitors were fabricated on a commercial textile and exhibited excellent performance, thus indicating the great potential for expanding the applications of supercapacitors.
Metabolic engineering of Esche..
A research team led by Professor Sang Yup Lee at the Korea Advanced Institute of Science and Technology has successfully developed a microorganism for producing a biodegradable plastic, polylactic acid (PLA). The importance of the study is in the novelty of producing a type of polymer that does not exist in nature by developing a synthetic pathway. It is also an eco-friendly finding because it has unparalleled bio-degradability in nature. Traditional ways to produce plastics have issues regarding the usage of petroleum-based chemicals, the depletion of natural resources, and pollution caused during the manufacturing process. Biorefineries that allow the production of valuable chemicals and materials from renewable carbon sources have been garnering increasing amounts of attention due to their potential to replace current production methods. This new finding allows for the production of PLA using a single-step fermentation process from renewable resources as opposed to the complex traditional two-step production method. This study was featured in various media, including CNN, the Economist, US New & World Report, and others.
Laser-based drug delivery into..
In 2011, professor Choi and his research team developed a novel method for drug delivery into the brain using light. The research team utilized a specialized laser, n ultrashort pulsed laser in this case, to open the blood-brain barrier (BBB) by activating the endothelial cells lining the blood vessels. Irradiation by ultrashort pulsed lasers has been shown to induce the intra-cellular events involved in calcium signaling, which can subsequently induce transient contraction of the endothelial cells and the opening of the BBB. This method can be applied as a safe and noninvasive tool for drug delivery into the brain.
Planning & scheduling system
□ Research Results ○ Approach #1 Scheduling using a manufacturing facility model on the basis of events - Manufacturing facility modeling using an event graph - Definition of a scheduling methodology on the basis of discrete event simulations # Scheduling & planning on the basis of Gantt chart simulations - Scheduling of a facility allotment scheme and release planning through Gantt chart creation simulations ○ Application area #1 Scheduling of a facility allotment scheme - Decision-making on time to replace the manufacturing products and parts for individual production facilities #2 Planning a workplace production scheme - Decision-making on manufacturing products and products volume for each production line #3 Future prediction, analysis and what-if simulation - Increment and diminution of production facilities, a what-if simulation study of changes of product mixes and constrained conditions ○ Research accomplishments - Scheduling methodology on the basis of discrete event simulations and system development - The venture company VMS Solutions was founded (technology prototype transfer) - Establishment of a scheduling system for LCD facilities of Samsung - Establishment of a scheduling system for the semiconductors facilities of Samsung - Development of a scheduling & planning methodology on the basis of Gantt chart simulations and system development (GCS methodology technology transfers) - Establishment of a planning system for a production scheme for each job task □ Excellency and Expected effects ○ Excellency - A scheduling & planning system on the basis of what-if simulations was adopted as a standard Samsung production scheme process for all production lines in 2011. - At present, the system is applied to LCD as well as semiconductor production lines. ※ Samsung Electronics along with Hynix Semiconductor account for approximately 50% of the semiconductor production volume overall. - Simulation-based production operation techniques performed in the laboratory have been transferred to a venture company and used in actual industrial areas. Advanced research is currently being carried out for continuous improvement techniques. - Samsung Electronics Co. gained the following favorable effects by applying the innovative scheduling & technology techniques: ? A decreased volume of corporate stock ? Increased productivity by as much as 15% ? Shortened turnaround times of 10% or above ? Improved import replacement effects by replacing S/W from advanced countries such as the USA with domestically produced S/W ? Improved Samsung production stage lines . FAB → EDS → Packaging → Testing → Moduling ○ Expected Effects - Helpful for establishing a production operation system during increases on the new production line through the use of the standardized production scheduling system □ Reference ? Published papers - B.K. Choi and B.H. Kim, "MES (manufacturing execution system) architecture for FMS compatible to ERP (enterprise planning system)", International Journal of CIM, Vol.15, No.3, pp.274-284, 2002 - Taedong Kim, B.K. Choi, Donghun Kang, JunYoung Lee, Duckwoong Lee, JaeHee Kim, "Gantt chart Simulation-based Job Change Planning for the LCD Industry", Proceedings of IFIP5.3. APMS (Advances in Production Management System) 2010 International Conference, 11-13 October 2010, Como, Italy
development of the industry’s ..
Professor Dai Gil Lee research team has successfully developed the industry’s first membrane-type cargo hold for LNG tankers. The newly developed cargo hold for LNG tankers was improved by VIL(Vibration Isolation Layer) and PRS(Pressure Resisting Structure). SCA (Smart Containment-System Advanced), the secondary protective wall system was developed using metallic materials and aerospace adhesive bonding, replacing the previous material of triplex that is made of glass fibers, for the first time in the world. The replacement of the material aimed to improve the gas tightness of the hold at -163℃. Developed SCA system, the cargo hold for LNG tankers, got technical certificate from Lloyd's Register of U.K. and ABS(American Bureau of Shipping) of U.S.A and held a launch ceremony at London, U.K. in April 2011. Korean shipbuilding company have finally tackled the last unsolved development initiative for the Korean shipbuilding industry, which was the cargo hold manufacturing technology for LNG tankers, completing a self-reliant Korean shipbuilding ecosystem."