본문 바로가기
대메뉴 바로가기
KAIST
Newsletter Vol.25
Receive KAIST news by email!
View
Subscribe
Close
Type your e-mail address here.
Subscribe
Close
KAIST
NEWS
유틸열기
홈페이지 통합검색
-
검색
KOREAN
메뉴 열기
SCIE
by recently order
by view order
The Real Time Observation of the Birth of a Molecule
From right to left: Dr. Kyung-Hwan Kim, Professor Hyotcherl Lhee, and Jong-Gu Kim, a Ph.D. candidate Professor Hyotcherl Lhee of the Department of Chemistry at KAIST and Japanese research teams jointly published their research results showing that they have succeeded in the direct observation of how atoms form a molecule in the online issue of Nature on February 19, 2015. The researchers used water in which gold atoms ([Au(CN) 2- ]) are dissolved and fired X-ray pulses over the specimen in femtosecond timescales to study chemical reactions taking place among the gold atoms. They were able to examine in real time the instant process of how gold atoms bond together to become a molecule, to a trimer or tetramer state. This direct viewing of the formation of a gold trimer complex ([Au(CN) 2- ] 3 ) will provide an opportunity to understand complex chemical and biological systems. For details, please see the following press release that was distributed by the High Energy Accelerator Research Organization, KEK, in Japan: Direct Observation of Bond Formations February 18, 2015 A collaboration between researchers from KEK, the Institute for Basic Science (IBS), the Korea Advanced Institute of Science and Technology (KAIST), RIKEN, and the Japan Synchrotron Radiation Research Institute (JASRI) used the SACLA X-ray free electron laser (XFEL) facility for a real time visualization of the birth of a molecular that occurs via photoinduced formation of a chemical bonds. This achievement was published in the online version of the scientific journal “Nature” (published on 19 February 2015). Direct “observation” of the bond making, through a chemical reaction, has been longstanding dream for chemists. However, the distance between atoms is very small, at about 100 picometer, and the bonding is completed very quickly, taking less than one picosecond (ps). Hence, previously, one could only imagine the bond formation between atoms while looking at the chemical reaction progressing in the test-tube. In this study, the research group focused on the process of photoinduced bond formation between gold (Au) ions dissolved in water. In the ground state (S 0 state in Fig. 1) Au ions that are weakly bound to each other by an electron affinity and aligned in a bent geometry. Upon a photoexcitation, the S 0 state rapidly converts into an excited (S 1 state in Fig. 1) state where Au-Au covalent bonds are formed among Au ions aligned in a linear geometry. Subsequently, the S 1 state transforms to a triplet state (T 1 state in Fig. 1) in 1.6 ps while accompanying further contraction of Au-Au bonds by 0.1 Å. Later, the T 1 state of the trimer converts to a tetramer (tetramer state in Fig. 1) on nanosecond time scale. Finally, the Au ions returned to their original loosely interacting bent structure. In this research, the direct observation of a very fast chemical reaction, induced by the photo-excitation, was succeeded (Fig. 2, 3). Therefore, this method is expected to be a fundamental technology for understanding the light energy conversion reaction. The research group is actively working to apply this method to the development of viable renewable energy resources, such as a photocatalysts for artificial photosynthesis using sunlight. This research was supported by the X-ray Free Electron Laser Priority Strategy Program of the MEXT, PRESTO of the JST, and the the Innovative Areas "Artificial Photosynthesis (AnApple)" grant from the Japan Society for the Promotion of Science (JSPS). Publication: Nature , 518 (19 February 2015) Title: Direct observation of bond formation in solution with femtosecond X-ray scattering Authors: K. H. Kim 1 , J. G. Kim 1 , S. Nozawa 1 , T. Sato 1 , K. Y. Oang, T. W. Kim, H. Ki, J. Jo, S. Park, C. Song, T. Sato, K. Ogawa, T. Togashi, K. Tono, M. Yabashi, T. Ishikawa, J. Kim, R. Ryoo, J. Kim, H. Ihee, S. Adachi. ※ 1: These authors contributed equally to the work. DOI: 10.1038/nature14163 Figure 1. Structure of a gold cyano trimer complex (Au(CN) 2 - ) 3 . Figure 2. Observed changes in the molecular structure of the gold complex Figure 3. Schematic view of the research of photo-chemical reactions by the molecular movie
2015.02.27
View 11289
KAIST Develops Subminiature, Power-Efficient Air Pollution Sensing Probe
Professor Inkyu Park and his research team from the Department of Mechanical Engineering at KAIST have developed a subminiature, power-efficient air-pollution sensing probe that can be applied to mobile devices. Their research findings were published online in the January 30th issue of Scientific Reports. As air pollution has increased, people have taken greater interest in health care. The developed technology could allow people to measure independently the air pollution level of their surrounding environments. Previous instruments used to measure air pollution levels were bulky and consumed a lot of power. They also often produced inaccurate results when measuring air pollution in which different toxic gases were mixed. These problems could not be resolved with existing semiconductor manufacturing process. Using local temperature field control technology, Professor Park’s team succeeded in integrating multiple heterogeneous nanomaterials and fitting them onto a small, low-power electronic chip. This microheating sensor can heat microscale regions through local hydrothermal synthesis. Because it requires a miniscale amount of nanomaterials to manufacture, the sensor is most suitable for mobile devices. Professor Park said, “Our research will contribute to the development of convergence technology in such field as air pollution sensing probes, biosensors, electronic devices, and displays.” The team's research was supported by the Ministry of Education and the Ministry of Science, ICT and Future Planning, Republic of Korea. Figure 1 – The Concept of Multiple Nanomaterial Device and Numerical Simulation Results of Precursor Solutions Figure 2 - Multiple Nanomaterial Manufactured in a Microscale Region
2015.02.27
View 9575
Professor Kwang-Hyun Cho Recognzied by "Scientist of the Month" Award
Professor Kwang-Hyun Cho of KAIST’s Department of Bio and Brain Engineering received the “Scientist of the Month” award in February 2015 from the Ministry of Science, ICT, and Future Planning of the Republic of Korea and the National Research Foundation of Korea. The award was in recognition of Professor Cho’s contribution to the advanced technique of controlling the death of cancer cells based on systems biology, a convergence research in information technology (IT) and biotechnology. Professor Cho has published around 140 articles in international journals, including 34 papers in renowned science journals such as Nature, Science, and Cell in the past three years. His work also includes systems biology textbooks and many entries in international academic encyclopaedia. His field, systems biology, is a new biological research paradigm that identifies and controls the fundamental principles of organisms on a systems level. A well-known tumour suppressor protein, p53, is known to suppress abnormal cell growth and promote apoptosis of can cells, and thus was a focus of research by many scientists, but its effect has been insignificant and brought many side effects. This was due to the complex function of p53 that controls various positive and negative feedbacks. Therefore, there was a limit to understanding the protein with the existing biological approach. However, Professor Cho found the kinetic change and function of p53 via a systems biology approach. By applying IT technology to complex biological networks, he also identified the response to stress and the survival and death signal transduction pathways of cardiomyocytes and developed new control methods for cancer cells. Professor Cho said, “This award served as a momentum to turn over a new leaf.” He added, “I hope convergence research such as my field will bring more innovative ideas on the boundaries of academia.”
2015.02.09
View 11461
KAIST's Thermoelectric Generator on Glass Fabric Receives the Grand Prize at the Netexplo Forum 2015
The forum announced top ten IT innovations expected to change the world and selected the grand prize on February 4, 2014. Established in 2007 by Martine Bidegain and Thierry Happe in partnership with the French Senate and the French Ministry for the Digital Economy, the Netexplo Observatory is an independent global organization that studies the impact of digital technology and innovation on society and business. Every year, the Netexplo Observatory hosts an international conference, the Netexplo Forum, in Paris, France, which surveys digital innovation worldwide. The 8th forum was held in partnership with the United Nations Educational, Scientific and Cultural Organization (UNESCO) on February 4-5, 2015, at the UNESCO House in Paris. Prior to the conference, the Netexplo Forum 2015 named the top ten most promising digital technologies that will greatly impact the world. Among them was Professor Byung Jin Cho’s research on a wearable thermoelectric generator (http://www.eurekalert.org/pub_releases/2014-04/tkai-tgo041014.php). The generator was selected as the most innovative technology this year. Professor Cho of KAIST’s Electrical Engineering Department developed a glass fabric-based thermoelectric generator that is extremely light and flexible and that produces electricity from the heat of the human body. This technology can be applied widely to wearable computers and mobile devices. The full list of innovations follows below: Wearable Thermo-Element, South Korea: The human body becomes a source of energy for mobile devices. W.Afate 3D-printer, Togo: An environmentally friendly fablab that makes a low-cost 3D-printer from recycling electronic components. Slack, USA: By combining email, Skype, and file-sharing and social networks, internal communication becomes much easier and simpler. PhotoMath, Croatia: A free app that enables smartphone users to solve mathematical problems simply by scanning the mathematical texts. Kappo, Chile: Connected cyclists produce and transmit useful data for urban planning to make the city more bike-friendly. Branching Minds, USA: An improved learning process for students in difficulty through a personalized approach. Baidu Kuai Sou, China: Smart chopsticks that can check food hazards. SCio, Israel: A pocket molecular sensor with various applications and data Rainforest Connection, USA: Fighting deforestation with recycled smartphones Sense Ebola Followup, Nigeria: A mobile tool to help contain Ebola For more details on the wearable thermos-element which received the 2015 Netexplo Award, please go to https://www.netexplo.org/en/intelligence/innovation/wearable-thermo-element. Pictures 1 and 2: A high-performance wearable thermoelectric generator that is extremely flexible and light. Picture 3: Senator Catherine Morin-Desailly (left) of the French Parliament presents the 2015 Netexplo Award to Professor Byung Jin Cho (right) on February 4, 2015 at the UNESCO House in Paris. Credit of Loran Dhérines Picture 4: Professor Byung Jin Cho (left) poses with Dr. Joël de Rosnay (right). Credit of Loran Dhérines
2015.02.06
View 12855
KAIST Develops a Method to Transfer Graphene by Stamping
Professor Sung-Yool Choi’s research team from KAIST's Department of Electrical Engineering has developed a technique that can produce a single-layer graphene from a metal etching. Through this, transferring a graphene layer onto a circuit board can be done as easily as stamping a seal on paper. The research findings were published in the January 14th issue of Small as the lead article. This technology will allow different types of wafer transfer methods such as transfer onto a surface of a device or a curved surface, and large surface transfer onto a 4 inch wafer. It will be applied in the field of wearable smart gadgets through commercialization of graphene electronic devices. The traditional method used to transfer graphene onto a circuit board is a wet transfer. However, it has some drawbacks as the graphene layer can be damaged or contaminated during the transfer process from residue from the metal etching. This may affect the electrical properties of the transferred graphene. After a graphene growth substrate formed on a catalytic metal substrate is pretreated in an aqueous poly vinyl alcohol (PVA) solution, a PVA film forms on the pretreated substrate. The substrate and the graphene layers bond strongly. The graphene is lifted from the growth substrate by means of an elastomeric stamp. The delaminated graphene layer is isolated state from the elastomeric stamp and thus can be freely transferred onto a circuit board. As the catalytic metal substrate can be reused and does not contain harmful chemical substances, such transfer method is very eco-friendly. Professor Choi said, “As the new graphene transfer method has a wide range of applications and allows a large surface transfer, it will contribute to the commercialization of graphene electronic devices.” He added that “because this technique has a high degree of freedom in transfer process, it has a variety of usages for graphene and 2 dimensional nano-devices.” This research was sponsored by the Ministry of Science, ICT and Future Planning, the Republic of Korea. Figure 1. Cover photo of the journal Small which illustrates the research findings Figure 2. Above view of Graphene layer transferred through the new method Figure 3. Large surface transfer of Graphene
2015.01.23
View 10238
KAIST Announces the Recipients of Distinguished Alumni Awards
The KAIST Alumni Association (KAA) announced four “Proud KAIST Alumni” awards recipients for the year 2014: Sung-Wook Park, the Chief Executive Officer and President of SK Hynix; Seung Ho Shin, the President of Kangwon National University; Kew-Ho Lee, the President of the Korea Research Institute of Chemical Technology; and Mun-Kee Choi, the former Minister of Science, ICT and Future Planning of the Republic of Korea. The award ceremony took place during the 2015 KAA’s New Year's ceremony on January 17, 2015 at the Palace Hotel in Seoul. Sung-Wook Park (M.S. ’82 and Ph.D. ’88, Department of Materials Science and Engineering), the Chief Executive Officer and President of SK Hynix, has worked as an expert in the field of memory semi-conductors for the past 30 years. He developed innovative technology and improved production efficiency, enabling the Korean semi-conductor industry to become a global leader. Seung Ho Shin (M.S. ’79 and Ph.D. ’87, Department of Physics), the President of Kangwon National University (KNU), worked in the field of optical information processing, producing excellent research achievements and teaching the next generation of scientists. As the president of KNU, he has set an exemplary leadership in higher education. Kew-Ho Lee (M.S. ’75, Department of Chemistry), the President of the Korea Research Institute of Chemical Technology, pioneered the field of separation film production which contributed greatly to Korean technological developments. He led several domestic and international societies to facilitate dynamic exchanges between industry and academia and with the international community. Mun-Kee Choi (M.S. ’76, Department of Industrial and Systems Engineering), the former Minister of Science, ICT and Future Planning, the Republic of Korea, is a great contributor to the information and communications technology in Korea, working as a leader in the field of broadband integrated service digital network. He is also an educator for gifted students in science and technology, and a manager of the Electronics and Telecommunications Research Institute. The Alumni Association established the “Proud KAIST Alumni Awards” in 1992 to recognize its alumni’s outstanding contributions to Korea and KAIST. Pictured from left to right, Sung-Wook Park (the Chief Executive Officer and President of SK Hynix), Seung Ho Shin (the President of Kangwon National University), Kew-Ho Lee (the President of the Korea Research Institute of Chemical Technology), and Mun-Kee Choi (the former Minister of Science, ICT and Future Planning)
2015.01.19
View 12719
A Key Signal Transduction Pathway Switch in Cardiomyocyte Identified
A KAIST research team has identified the fundamental principle in deciding the fate of cardiomyocyte or heart muscle cells. They have determined that it depends on the degree of stimulus in β-adrenergic receptor signal transduction pathway in the cardiomyocyte to control cells' survival or death. The findings, the team hopes, can be used to treat various heart diseases including heart failure. The research was led by KAIST Department of Bio and Brain Engineering Chair Professor Kwang-Hyun Cho and conducted by Dr. Sung-Young Shin (lead author) and Ph.D. candidates Ho-Sung Lee and Joon-Hyuk Kang. The research was conducted jointly with GIST (Gwangju Institute of Science and Technology) Department of Biological Sciences Professor Do-Han Kim’s team. The research was supported by the Ministry of Science, ICT and Future Planning, Republic of Korea, and the National Research Foundation of Korea. The paper was published in Nature Communications on December 17, 2014 with the title, “The switching role of β-adrenergic receptor signalling in cell survival or death decision of cardiomyocytes.” The β-adrenergic receptor signal transduction pathway can promote cell survival (mediated by β2 receptors), but also can result in cell death by inducing toxin (mediated by β1 receptors) that leads to various heart diseases including heart failure. Past attempts to identify the fundamental principle in the fate determining process of cardiomyocyte based on β-adrenergic receptor signalling concluded without much success. The β-adrenergic receptor is a type of protein on the cell membrane of cardiomyocyte (heart muscle cell) that when stimulated by neurohormones such as epinephrine or norepinephrine would transduce signals making the cardiomyocyte contract faster and stronger. The research team used large-scale computer simulation analysis and systems biology to identify ERK* and ICER** signal transduction pathways mediated by a feed-forward circuit as a key molecular switch that decides between cell survival and death. Weak β-adrenergic receptor stimulations activate ERK signal transduction pathway, increasing Bcl-2*** protein expression to promote cardiomyocyte survival. On the other hand, strong β-adrenergic receptor stimulations activate ICER signal transduction pathway, reducing Bcl-2 protein expression to promote cardiomyocyte death. Researchers used a systems biology approach to identify the mechanism of B-blocker****, a common drug prescribed for heart failure. When cardiomyocyte is treated with β1 inhibitor, strong stimulation on β-adrenergic receptor increases Bcl-2 expression, improving the chance of cardiomyocyte survival, a cell protection effect. Professor Kwang-Hyun Cho said, “This research used systems biology, an integrated, convergence research of IT (information technology) and BT (biotechnology), to successfully identify the mechanism in deciding the fate of cardiomyocytes based on the β-adrenergic receptor signal transduction pathway for the first time. I am hopeful that this research will enable the control of cardiomyocyte survival and death to treat various heart diseases including heart failure.” Professor Cho’s team was the first to pioneer a new field of systems biology, especially concerning the complex signal transduction network involved in diseases. Their research is focused on modelling, analyzing simulations, and experimentally proving signal pathways. Professor Cho has published 140 articles in international journals including Cell, Science, and Nature. * ERK (Extracellular signal-regulated kinases): Signal transduction molecule involved in cell survival ** ICER (Inducible cAMP early repressor): Signal transduction molecule involved in cell death *** Bcl-2 (B-cell lymphoma 2): Key signal transduction molecule involved in promotion of cell survival **** β-blocker: Drug that acts as β-adrenergic receptor inhibitor known to slow the progression of heart failure, hence used most commonly in medicine. Picture: A schematic diagram for the β-AR signalling network
2015.01.05
View 12277
Broadband and Ultrathin Polarization Manipulators Developed
Professor Bumki Min from the Department of Mechanical Engineering at KAIST has developed a technology that can manipulate a polarized light in broadband operation with the use of a metamaterial. It is expected that this technology will lead to the development of broadband optical devices that can be applied to broadband communication and display. When an object or its structure is analyzed by using a polarized light such as a laser, the results are generally affected by the polarized state of the light. Therefore, in an optics laboratory, the light is polarized by various methods. In such cases, researchers employ wave plates or photoactive materials. However, the performance of these devices depend vastly on wavelength, and so they are not suitable to be used as a polarizer, especially in broadband. There were many attempts to make artificial materials that are very photoactive by using metamaterials which have a strong resonance. Nonetheless, because the materials had an unavoidable dispersion in the resonance frequency, they were not adequate for broadband operation. Professor Min’s research team arranged and connected helical metamaterials that are smaller than the wavelength of light. They verified theoretically and experimentally that polarized light can be constantly rotated regardless of the wavelength by super-thin materials that have thickness less than one-tenth of the wavelength of the light. The experiment which confirmed the theory was conducted in the microwave band. Broadband polarized rotational 3D metamaterials were found to rotate the polarized microwave within the range of 0.1 GHz to 40 GHz by 45 degrees regardless of its frequency. This nondispersive property is quite unnatural because it is difficult to find a material that does not change in a wide band. In addition, the research team materialized the broadband nondispersive polarized rotational property by designing the metamaterial in a way that it has chirality, which determines the number of rotations proportional to the wavelength. Professor Min said, “As the technology is able to manipulate ultrathin polarization of light in broadband, it will lead to the creation of ultra-shallow broadband optical devices.” Sponsored by the Ministry of Science, ICT and Future Planning of the Republic of Korea and the National Research Foundation of Korea, this research was led by a PhD candidate, Hyun-Sung Park, under the guidance of Professor Min. The research findings were published online in the November 17th issue of Nature Communications. Figure 1 – Broadband and Ultrathin Polarization Manipulators Produced by 3D Printer Figure 2 – Concept of Broadband and Ultrathin Polarization Manipulators
2014.12.03
View 10499
President Steve Kang will serve as the Chairman of Global Agenda Council on the Future of Electronics of the World Economic Forum
President Steve Kang of KAIST has been appointed to the Chairman of the Global Agenda Council (GAC) on the Future of Electronics of the World Economic Forum (WEF). He will serve the position for two years until September 2016. President Kang and WEF council members co-hosted, with the government of the United Arab Emirates (UAE), the Future Circles Initiative, a future-focused, innovative brainstorming conference to help find strategies and ideas for the development of UAE. The conference took place on November 11-12, 2014 at the Mina Al Salam Hotel in Dubai. WEF has about 80 GACs. Each council consists of 15 experts and thought leaders from the academia, industry, government, business, and non-profit sector and deals with specific issues that are important and relevant to the global community such as ageing, artificial intelligence and robotics, brain research, food and nutrition security, education, social media, and future of chemicals, advanced materials and biotechnology. President Kang was recognized for his contribution to the advancement of science and higher education as an engineer, scholar, and professor. He led the development of the world’s premier CMOS 32-bit microprocessors while working at the AT&T Bell Laboratories. He also taught and conducted research at the University of California, Santa Cruz, and the University of Illinois, Urbana-Champaign. President Kang served as the chancellor of the University of California at Merced from March 2007 to June 2011.
2014.11.11
View 8265
Professor Sung-Yong Kim Receives the Young Scientist Award
Professor Sung-Yong Kim of the Department of Ocean Systems Engineering at KAIST received the Young Scientist Award for 2014 conferred by the Korean Society of Oceanography (KSO). The award was presented at the KSO’s fall conference that took place on November 6, 2014 at the campus of the Naval Academy of the Republic of Korea in Jinhae. Professor Kim has been recognized for his outstanding research in coastal oceanography and environmental fluid mechanics. His research papers are frequently published in prestigious journals such as the Journal of Geophysical Research-Oceans by the American Geophysical Union.
2014.11.11
View 7118
President Steve Kang of KAIST Attends the 2014 Summer Davos Forum in Tianjin, China
President Steve Kang of KAIST will attend the 2014 Annual Meeting of the New Champions, the World Economic Forum (WEF), to be held on September 10-12, 2014 in Tianjin, China. KAIST holds its own IdeasLab session on nanotechnology on September 12, 2014. On September 10, 2014, President Steve Kang will participate in a private session hosted by the Global University Leaders Forum (GULF) community at WEF as a panelist. In addition to President Kang, eight presidents from top global universities such as the National University of Singapore, Peking University, ETH Zurich (Swiss Federal Institute of Technology), University of Tokyo, and Carnegie Mellon University will join the panel discussion under the topic, “Increasing the Translational Impact of University Research.” Specifically, the presidents will address issues related to the importance of university-led technology transfer in Asia, key strategies and goals for technology transfer, and implementation approaches taken by each university to promote technology transfer from university to industry. President Kang was invited to this GULF session, the only attendant from Korean universities, in recognition of his long time experience and expertise in education and research. In 2006, WEF created the GULF, a small community of the presidents of top universities in the world, aiming to offer an open platform for high-level dialogues on issues of higher education and research with other sectors, as well as to foster collaboration between universities in areas of significance for global policy. As of 2014, a total of 25 globally leading universities, including Harvard University, University of Cambridge, and Massachusetts Institute of Technology, are GULF members. KAIST, which joined the club this year, is the only Korean university. The 2014 Annual Meeting of the New Champions, also known as the Summer Davos Forum, hosts numerous sessions under the theme of “Creating Value through Innovation.” At the Forum, a total of ten IdeasLab sessions will be hosted. KAIST was invited to run its own IdeasLab on nanotechnology on September 12, 2014. Together with President Kang, Professors Sang Ouk Kim and Keon Jae Lee from the Department of Materials Science Engineering, KAIST, and Professors Sang Yup Lee and Hyunjoo Lee from the Department of Chemical and Biomolecular Engineering, KAIST, will present their own speeches on the topic entitled “From diagnostics to materials, how is nanotechnology changing lives?” President Kang will give the opening speech at the KAIST IdeasLab. He said that an invitation from WEF to join the IdeasLab spoke well for KAIST: “KAIST is the first and the only Korean university ever invited to run its own IdeasLab at the World Economic Forum. The IdeasLab is an expert group meeting, conducted only by the world’s most prestigious universities and research institutes. At the IdeasLab sessions, global leaders from different sectors identify major issues facing higher education and humanity and explore solutions through science and technology innovation. Holding our own IdeasLab on one of our strongest fields, nanotechnology, is indeed an excellent opportunity for KAIST to show its strength in academic and research excellence on the global stage.”
2014.09.08
View 12656
News Article on the Development of Synthesis Process for Graphene Quantum Dots
Before It's News, an international online news agency, highlighted the recent research conducted by KAIST professors (Seokwoo Jeon of the Department of Materials Science and Engineering, Yong-Hoon Cho of the Department of Physics, and Seunghyup Yoo of the Department of Electrical Engineering) on the development of synthesis process for graphene quantum dots, nanometer-sized round semiconductor nanoparticles that are very efficient at emitting photons. If commercialized, this synthetic technology will lead the way to the development of paper-thin displays in the future. For the article, please go to the link below: Before It’s News, September 3, 2014“Graphene quantum dots prove highly efficient in emitting light” http://beforeitsnews.com/science-and-technology/2014/09/graphene-quantum-dots-prove-highly-efficient-in-emitting-light-2718190.html
2014.09.07
View 11693
<<
첫번째페이지
<
이전 페이지
11
12
13
14
15
16
17
18
19
20
>
다음 페이지
>>
마지막 페이지 35