IEEE
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Omnidirectional Free Space Wireless Charging Developed
The simultaneous charging of multiple mobile devices at 0.5 meter away from the power source is now possible under the international electromagnetic field guidelines.
Mobile devices, such as smartphones and laptops, have become indispensable portable items in modern life, but one big challenge remains to fully enjoying these devices: keeping their batteries charged.
A group of researchers at KAIST has developed a wireless-power transfer (WPT) technology that allows mobile devices to be charged at any location and in any direction, even if the devices are away from the power source, just as Wi-Fi works for Internet connections. With this technology, so long as mobile users stay in a designated area where the charging is available, e.g., the Wi-Power zone, the device, without being tethered to a charger, will pick up power automatically, as needed.
The research team led by Professor Chun T. Rim of the Nuclear and Quantum Engineering Department at KAIST has made great strides in WPT development. Their WPT system is capable of charging multiple mobile devices concurrently and with unprecedented freedom in any direction, even while holding the devices in midair or a half meter away from the power source, which is a transmitter. The research result was published in the June 2015 on-line issue of IEEE Transactions on Power Electronics, which is entitled “Six Degrees of Freedom Mobile Inductive Power Transfer by Crossed Dipole Tx (Transmitter) and Rx (Receiver) Coils.”
Professor Rim’s team has successfully showcased the technology on July 7, 2015 at a lab on KAIST’s campus. They used high-frequency magnetic materials in a dipole coil structure to build a thin, flat transmitter (Tx) system shaped in a rectangle with a size of 1m2. Either 30 smartphones with a power capacity of one watt each or 5 laptops with 2.4 watts each can be simultaneously and wirelessly charged at a 50 cm distance from the transmitter with six degrees of freedom, regardless of the devices’ three-axes positions and directions. This means that the device can receive power all around the transmitter in three-dimensional space. The maximum power transfer efficiency for the laptops was 34%. The researchers said that to fabricate plane Tx and Rx coils with the six-degree-of-freedom characteristic was a bottleneck of WPT for mobile applications.
Dipole Coil Resonance System (DCRS)
The research team used the Dipole Coil Resonance System (DCRS) to induce magnetic fields, which was developed by the team in 2014 for inductive power transfer over an extended distance. The DCRS is composed of two (transmitting and receiving) magnetic dipole coils, placed in parallel, with each coil having a ferrite core and connected with a resonant capacitor. Comparing to a conventional loop coil, the dipole coil is very compact and has a less dimension. Therefore, a crossed dipole structure has 2-dimension rather than 3-dimension of a crossed loop coil structure. The DCRS has a great advantage to transfer power even when the resonance frequency changes in the range of 1% (Q factor is below 100). The ferrite cores are optimally designed to reduce the core volume by half, and their ability to transfer power is nearly unaffected by human bodies or surrounding metal objects, making DCRS ideal to transmit wireless power in emergency situations. In a test conducted in 2014, Professor Rim succeeded in transferring 209 watts of power wirelessly to the distance of five meters. (See KAIST’s press release on DCRS for details: http://www.eurekalert.org/pub_releases/2014-04/tkai-wpt041714.php.)
Greater Flexibility and Safer Charging
The research team rearranged the two dipole coils from a parallel position to cross them in order to generate rotating magnetic fields, which was embedded in the Tx’s flat platform. This has made it possible for mobile devices to receive power from any direction.
Although wireless-power technology has been applied to smartphones, it could not offer any substantial advantages over traditional wired charging because the devices still require close contact with the transmitter, a charging pad. To use the devices freely and safely, including in public spaces, the WPT technology should provide mobile users with six degrees of freedom at a distance. Until now, all wireless-charging technologies have had difficulties with the problem of short charging distance, mostly less than 10 cm, as well as charging conditions that the devices should be placed in a fixed position. For example, the Galaxy S6 could only be charged wirelessly in a fixed position, having one degree of freedom. The degree of freedom represents mobile devices’ freedom of movement in three-dimensional space.
In addition, the DCRS works at a low magnetic field environment. Based on the magnetic flux shielding technology developed by the research team, the level of magnetic flux is below the safety level of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guideline (27µT) for general public exposure to electromagnetic field (EMF).
Professor Rim said, “Our transmitter system is safe for humans and compatible with other electronic devices. We have solved three major issues of short charging distance, the dependence on charging directions, and plane coil structures of both Tx and Rx, which have blocked the commercialization of WPT.”
Currently, the research team and KAIST’s spin-off company, TESLAS, Inc., have been conducting pilot projects to apply DCRS in various places such as cafes and offices.
YouTube Link: https://www.youtube.com/watch?v=JU64pMyJioc
Demonstration of 30 Watts Range Omnidirectional Wireless-charging at a Laboratory on KAIST’s Campus
Figure 1: Wide-range omnidirectional wireless-charging system based on DCRS can charge multiple numbers of mobile devices simultaneously in a 1m3 range. The above is a transmitter, and the below is a Samsung Galaxy Note with a receiver embedded inside.
Figure 2: Demonstration of the omnidirectional wireless-charging system (clockwise from top of the left, robust charging despite the presence of metal obstacles, omnidirectional charging, long distance charging, and multiple devices charging)
2015.07.08 View 16002 -
KAIST Professor Sung-Ju Lee Appointed a Technical Program Chair of INFOCOM
Professor Sung-Ju Lee of the Department of Computer Science at KAIST has been appointed to serve as a technical program chair of IEEE INFOCOME. The computer communication conference, started in 1982, is influential in the research fields of the Internet, wireless, and data centers.
Professor Lee is the first Korean to serve as a program chair. He has been acknowledged for his work in network communications. In the 34th conference, which will be held next year, he will take part in selecting 650 experts in the field to become members and supervise the evaluation of around 1,600 papers.
Professor Lee is the leading researcher in the field of wireless mobile network systems. He is a fellow of the Institute of Electrical and Electronics Engineers (IEEE) and served as the general chair of the 20th Association for Computing Machinery (ACM) SIGMOBILE Annual International Conference on Mobile Computing & Networking (MobiCom 2014). He is on the editorial boards of IEEE Transactions on Mobile Computing (TMC) and IEEE Internet of Things Journals.
Professor Lee said, “I hope to continue the traditions of the conference, as well as integrating research from various areas of network communication. I will strive to create a program with high technology transfer probability.”
The 34th IEEE INFOCOM will take place in San Francisco in April 2016.
2015.07.02 View 7318 -
Professor Kyoungsik Yu Receives the Young IT Engineer Award from IEEE and IEIE of Korea
Professor Kyoungsik Yu of KAIST’s Department of Electrical Engineering is the recipient of this year’s Young IT (Information Technology) Engineer Award that was co-hosted by the Institute of Electrical and Electronics Engineers (IEEE), the Institute of Electronics Engineers of Korea (IEIE), and Haedong Science Culture Foundation in Korea. The award was presented on June 22, 2015 at The Ramada Plaza Jeju Hotel on Jeju Island, Korea.
The Young IT Engineer Award is given to emerging scientists who have made significant contributions to the advancement of technology, society, environment, and creative education.
Professor Yu's main research interests are IT, energy, and imaging through miniaturization and integration of optoelectronic devices. His contribution to academic and technological development is reflected in his publication of more than 100 papers in international journals and conferences, which were cited over 2,200 times.
Professor Yu said, “I’m honored to receive this award and am encouraged by it. I also find the award meaningful because the United Nations has designated this year as the “International Year of Light and Light-based Technologies,” the field I have been involved in as a researcher.”
In addition to Korea, the IEEE has jointly hosted and presented this award to researchers in countries such as Chile, Ecuador, Peru, Singapore, and Italy.
2015.06.22 View 9993 -
World Renowned Wireless Technology Experts Gathered in KAIST
KAIST hosted the 2015 IEEE WoW from June 5 to 6, 2015
Wireless power transfer technologies, such as wireless electric vehicles, trains and batteries, are increasingly in use. A conference, The 2015 IEEE WoW (Workshop on Wireless Power), was held in KI Building for two days starting June 5, 2015 to exchange ideas on the new trends and issues of the world wireless power technology.
The wireless power conference hosted by Institute of Electrical and Electronics Engineers (IEEE), IEEE WoW, was sponsored by its societies, PELS, IAS, IES, VTS, MAG, and PES.
This year’s conference took place in Korea for the first time and was titled “IEEE PELS Workshop on Emerging Technologies: Wireless Power.” The event was attended by around 200 experts in wireless power from 15 countries to discuss the international standards and current trends.
Keynote speakers were President Don Tan of IEEE; Professor Grant Covic of the University of Auckland; Andrew Daga, the CEO at Momentum Dynamics Corporation; Professor Ron Hui of the City University of Hong Kong; and Jung Goo Cho, the CEO of Green Power Technologies.
The forum included plenary speaking sessions on “The Futures of EV and Power Electronics,” “Development of IPT at the University of Auckland,” “Interoperable Solution for Wireless EV Charging,” “Development of IPT for Factory Automation,” “Commercialization of High Power WPT,” and “WPT: From Directional Power to Omni-directional Power.”
Notably, KAIST Professor Dong-Ho Cho, responsible for KAIST’s On-Line Electric Vehicle (OLEV) development, spoke on “The Development of Shaped Magnetic Field Systems for EVs and Trains” to introduce the KAIST OLEV bus and OLEV trains developed in cooperation with Korea Railroad Research Institute.
The Dialog Sessions on “The Futures of Wireless Electric Vehicles” were led by John M. Miller of JNJ Miller and “Road Charged EV and WPT Regulation and Standard for EV in Japan” by Yoichi Hori of University of Tokyo.
The General Chair of this year’s IEEE WoW, KAIST Professor Chun T. Rim said, “This forum serves a great assistance to the industry using wireless power technology in areas such as smartphones, home appliances, Internet of Things, and wearable devices.”
2015.05.29 View 8210 -
Professor Shim Featured with His Drone System in IEEE Spectrum
The IEEE Spectrum, a technology and science magazine published by the Institute of Electrical and Electronics Engineers (IEEE), featured an article of KAIST’s autonomous unmanned aerial vehicles (UAVs) entitled “South Korea Prepares for Drone vs. Drone Combat,” posted on April 1, 2015.
The article introduces the anti-drone defense system being developed by Professor “David” Hyunchul Shim of the Department of Aerospace Engineering at KAIST. With the goal of developing guard drones that can detect and capture unknown UAVs, the anti-drone defense system consists of reconnaissance drones, agile multi-rotor UAVs equipped with nets which are dropped to snare enemy drones, and transport UAVs to carry smaller drones.
Professor Shim currently leads KAIST’s Unmanned System Research Group (USRG, http://unmanned.kaist.ac.kr/) and Center of Field Robotics for Innovation, Exploration, aNd Defense (C-FRIEND).
For the article, please go to http://spectrum.ieee.org/automaton/robotics/aerial-robots/south-korea-drone-vs-drone.
2015.04.02 View 11434 -
PIBOT, a small humanoid robot flies an aircraft
The 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2014) took place in Chicago, Illinois, on September 14-18, 2014.
Professor David Hyunchul Shim and his students from the Department of Aerospace Engineering, KAIST, presented a research paper entitled “A Robot-machine Interface for Full-functionality Automation Using a Humanoid” at the conference.
The robot called “PIBOT,” a pint-sized, tiny humanoid robot, uses a mixture of flight data and visuals to fly an airplane, capable of identifying and operating all of the buttons and switches in the cockpit of a normal light aircraft designed for humans.
For now, the robot is only flying a simulator, but Professor Shim expects that “PIBOT will help us have a fully automated flight experience, eventually replacing human pilots.”
The IEEE Spectrum magazine published an article on PIBOT posted online September 18, 2014. Please follow the link below for the article:
IEEE Spectrum, September 18, 2014
Tiny Humanoid Robot Learning to Fly Real Airplanes
http://spectrum.ieee.org/automaton/robotics/humanoids/tiny-humanoid-robot-learning-to-fly-real-airplanes
2014.09.23 View 12324 -
Tae-Wan Kim, a doctoral candidate, receives the best paper award from ECTC
The 2014 Electronic Components and Technology Conference (ECTC) will take place on May 27-30 in Florida, USA. Tae-Wan Kim, a Ph.D. candidate at the Department of Materials Science Engineering (MSE), KAIST, will receive the Intel Best Student Paper Award at the conference.ECTC is the premier international conference that brings together the best researchers and engineers in packaging, components and microelectronic systems science, technology and education in an environment of cooperation and technical exchange. The conference is sponsored by the Components, Packaging and Manufacturing Technology (CPMT) Society of IEEE (Institute of Electrical and Electronics Engineering).The paper describes research on novel nanofiber anisotropic conductive films for ultra fine pitch electronic package application, which was written under the guidance of Professor Kyung-Wook Paik of the MSE Department. In the past ten years, two of his students have received the best paper award from ECTC.
2014.03.14 View 10175 -
Is it possible to identify rumors on SNS?
Rumors
sporadically spread with people with fewer followers in the centerResearched
over 100 rumors in the US from 2006 to 2009 Is it
possible to filter information on SNS such as Twitter and Facebook? A research
team led by Professor Mee-Young Cha from the Department of Cultural Technology
Graduate School at KAIST, Professor Kyo-Min Jung of Seoul National University,
Doctor Wei Chen and Yajun Wang of Microsoft Asia, has developed a technology
that can accurately filter out information on Twitter to 90% accuracy. The
research not only deduced a new mathematical model, network structure, and
linguistic characteristics on rumors from SNS data, but is also expected to
enhance the effort to make secure technology to regulate Internet rumors. The team
analysed the characteristics of rumors in over 100 widespread cases in the US
from 2006 to 2009 on Twitter. The team gathered data, which included a range of
areas such as politics, IT, health and celebrity gossips, and their analysis
could identify rumors to 90% accuracy. The filtering was more accurate in
rumors that included slanders or insults. The
research team identified three characteristics of the spread of rumors. Firstly,
rumors spread continuously. Normal news spreads widely once and is mentioned
rarely again on media, but rumors tend to continue for years. Secondly,
rumors spread through sporadic participation of random users with no
connections. Rumors start from people with fewer followers and spread to the
more popular. This phenomenon is often observed in rumors concerning
celebrities or politicians. Lastly,
rumors have unique linguistic characteristics. Rumors frequently include words
(such as “it may be true,” “although not certain, I think,” “although I cannot
fully remember”) related to psychological processes that question, deny, or
infer the reliability of the information. Professor
Cha said, “This research deduced not only a statistical and mathematical model
but also is an integrated research on social psychological theory on the
characteristics of rumors that attract great attention from the society based
on ample data.” The results
were made public in IEEE International Conference on Data Mining last December
in Texas, USA.
2014.02.03 View 9447 -
Hyun-Sik Kim, KAIST doctoral student, receives Predoctoral Achievement Award from IEEE Solid-State Circuits Society
Hyun-Sik Kim, a Ph.D. student from the Department of Electrical Engineering, is scheduled to receive the “Predoctoral Achievement Award” from the Institute of Electrical and Electronics Engineers (IEEE) Solid-State Circuit Society (SSCS) at its 2014 annual conference to be held on February 9-13 in San Francisco, USA. Kim, the first Korean student receiving the award, will also be given a 1,000 USD honorarium.
Established in 1983, the Predoctoral Achievement Award has been given to a small number of promising graduate students, which is made on the basis of academic record and potential, quality of publications, and a graduate study program well matched to the charter of SSCS. Among the previous recipients were Professor Bernhard Boser of the University of California in Berkeley and Professor Michael Flynn of Michigan University.
Kim published 15 research papers in international journals and conferences, applied for 35 domestic and international patents, and received the best paper award in human technology from Samsun Electronics for three consecutive years.
Professor Kyu-Hyung Cho of Electrical Engineering is Kim's principal advisor.
2014.01.27 View 9645 -
Professor Kwy-Ro Lee Appointed Distinguished Member of IEEE
Professor Kwy-Ro Lee from the Department of Electrical Engineering at KAIST was selected as a distinguished member of the Institute of Electrical and Electronics Engineers (IEEE) where his contribution to research development of the technological management of semiconductors was recognized.
Professor Lee earned his BS from Seoul National University and MS & Ph.D. from the University of Minnesota. He has been working as a professor in the Department of Electrical Engineering since 1986. He has also served as the president of the LG Electronics Research Center in 2005 and the president of the Nanoscience and Technology Center at KAIST in 2010.
IEEE is the largest professional association for the advancement of technology in electrical, electronics, computing and communication with 400,000 members in 160 countries. Only 0.1 percent of members with over ten years of service can be selected as distinguished members based on their research devotion for society.
2014.01.02 View 7544 -
Professor Chun-Taek Rim Appointed as Associate Editor for IEEE TPEL
Professor Chun-Taek Rim of the nuclear and quantum engineering at KAIST was appointed as an associate editor of the Institute of Electrical and Electronics Engineers (IEEE) Transactions on Power Electronics (TPEL), an eminent academic journal bio-monthly published in the field of power electronics.The journal has a high impact factor (4.08), a measure reflecting the average number of citations to recent articles published in an academic journal, which ranks as the 6th the most influential journal among the 100 journals published by IEEE.Professor Rim was also appointed to an associate editor for IEEE Journal of Emerging and Selected Topics in Power Electronics in September in recognition of his expertise in wireless power and electric vehicles.
2013.11.15 View 9853 -
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 12043