본문 바로가기
대메뉴 바로가기
KAIST
Newsletter Vol.26
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
AI
by recently order
by view order
Top Ten Ways Biotechnology Could Improve Our Everyday Life
The Global Agenda Council on Biotechnology, one of the global networks under the World Economic Forum, which is composed of the world’s leading experts in the field of biotechnology, announced on February 25, 2013 that the council has indentified “ten most important biotechnologies” that could help meet rapidly growing demand for energy, food, nutrition, and health. These new technologies, the council said, also have the potential to increase productivity and create new jobs. “The technologies selected by the members of the Global Agenda Council on Biotechnology represent almost all types of biotechnology.Utilization of waste, personalized medicine,and ocean agricultureare examples of the challenges where biotechnology can offer solutions,”said Sang Yup Lee, Chair of the Global Agenda Council on Biotechnology and Distinguished Professor in the Department of Chemical and Biomolecular Engineering at the Korea Advanced Institute of Science and Technology (KAIST). He also added that “the members of the council concluded that regulatory certainty, public perception, and investment are the key enablers for the growth of biotechnology.” These ideas will be further explored during “Biotechnology Week” at the World Economic Forum’s Blog (http://wef.ch/blog) from Monday, 25 February, 2013. The full list follows below: Bio-based sustainable production of chemicals, energy, fuels and materials Through the last century, human activity has depleted approximately half of the world’s reserves of fossil hydrocarbons. These reserves, which took over 600 million years to accumulate, are non-renewable and their extraction, refining and use contribute significantly to human emissions of greenhouse gases and the warming of our planet. In order to sustain human development going forward, a carbon-neutral alternative must be implemented. The key promising technology is biological synthesis; that is, bio-based production of chemicals, fuels and materials from plants that can be re-grown. Engineering sustainable food production The continuing increase in our numbers and affluence are posing growing challenges to the ability of humanity to produce adequate food (as well as feed, and now fuel). Although controversial, modern genetic modification of crops has supported growth in agricultural productivity. In 2011, 16.7 million farmers grew biotechnology-developed crops on almost 400 million acres in 29 countries, 19 of which were developing countries. Properly managed, such crops have the potential to lower both pesticide use and tilling which erodes soil. Sea-water based bio-processes Over 70% of the earth surface is covered by seawater, and it is the most abundant water source available on the planet. But we are yet to discover the full potential of it. For example with halliophic bacteria capable of growing in the seawater can be engineered to grow faster and produce useful products including chemicals, fuels and polymeric materials. Ocean agriculture is also a promising technology. It is based on the photosynthetic biomass from the oceans, like macroalgae and microalgae. Non-resource draining zero waste bio-processing The sustainable goal of zero waste may become a reality with biotechnology. Waste streams can be processed at bio-refineries and turned into valuable chemicals and fuels, thereby closing the loop of production with no net waste. Advances in biotechnology are now allowing lower cost, less draining inputs to be used, including methane, and waste heat. These advances are simplifying waste streams with the potential to reduce toxicity as well as support their use in other processes, moving society progressively closer to the sustainable goal of zero waste. Using carbon dioxide as a raw material Biotechnology is poised to contribute solutions to mitigate the growing threat of rising CO2 levels. Recent advances are rapidly increasing our understanding of how living organisms consume and use CO2. By harnessing the power of these natural biological systems, scientists are engineering a new wave of approaches to convert waste CO2 and C1 molecules into energy, fuels, chemicals, and new materials. Regenerative medicine Regenerative medicine has become increasingly important due to both increased longevity and treatment of injury. Tissue engineering based on various bio-materials has been developed to speed up the regenerative medicine. Recently, stem cells, especially the induced pluripotent stem cells (iPS), have provided another great opportunity for regenerative medicine. Combination of tissue engineering and stem cell (including iPS) technologies will allow replacements of damaged or old human organs with functional ones in the near future. Rapid and precise development and manufacturing of medicine and vaccines A global pandemic remains one of the most real and serious threats to humanity. Biotechnology has the potential to rapidly identify biological threats, develop and manufacture potential cures. Leading edge biotechnology is now offering the potential to rapidly produce therapeutics and vaccines against virtually any target. These technologies, including messenger therapeutics, targeted immunotherapies, conjugated nanoparticles, and structure-based engineering, have already produced candidates with substantial potential to improve human health globally. Accurate, fast, cheap, and personalized diagnostics and prognostics Identification of better targets and combining nanotechnology and information technology it will be possible to develop rapid, accurate, personalized and inexpensive diagnostics and prognostics systems. Bio-tech improvements to soil and water Arable land and fresh water are two of the most important, yet limited, resources on earth. Abuse and mis-appropriation have threatened these resources, as the demand on them has increased. Advances in biotechnology have already yielded technologies that can restore the vitality and viability of these resources. A new generation of technologies: bio-remediation, bio-regeneration and bio-augmentation are being developed, offering the potential to not only further restore these resources, but also augment their potential. Advanced healthcare through genome sequencing It took more than 13 years and $1.5 billion to sequence the first human genome and today we can sequence a complete human genome in a single day for less than $1,000. When we analyze the roughly 3 billion base pairs in such a sequence we find that we differ from each other in several million of these base pairs. In the vast majority of cases these difference do not cause any issues but in rare cases they cause disease, or susceptibility to disease. Medical research and practice will increasingly be driven by our understanding of such genetic variations together with their phenotypic consequences.
2013.03.19
View 13013
KAIST Develops Wireless Power Transfer Technology for High Capacity Transit
KAIST and the Korea Railroad Research Institute (KRRI) have developed a wireless power transfer technology that can be applied to high capacity transportation systems such as railways, harbor freight, and airport transportation and logistics. The technology supplies 60 kHz and 180 kW of power remotely to transport vehicles at a stable, constant rate. KAIST and KRRI successfully showcased the wireless power transfer technology to the public on February 13, 2013 by testing it on the railroad tracks at Osong Station in Korea. Originally, this technology was developed as part of an electric vehicle system introduced by KAIST in 2011 known as the On-line Electric Vehicle (OLEV). OLEV does not need to be parked at a charging station to have a fully powered battery. It gets charged while running, idling, and parking, enabling a reduction in size of the reserve battery down to one-fifth of the battery on board a regular electric car. The initial models of OLEV, a bus and a tram, receive 20 kHz and 100 kW power at an 85% transmission efficiency rate while maintaining a 20cm air gap between the underbody of vehicle and the road surface. OLEV complies with the national and international standards of 62.5 mG, a safety net for electromagnetic fields. In July 2013, for the first time since its development, OLEV will run on a regular road, an inner city route in the city of Gumi, requiring 40 minutes of driving each way. Today’s technology demonstration offers further support that OLEV can be utilized for large-scale systems. Professor Dong-Ho Cho, Director of Center for Wireless Power Transfer Technology Business Development at KAIST, explained the recent improvements to OLEV: “We have greatly improved the OLEV technology from the early development stage by increasing its power transmission density by more than three times. The size and weight of the power pickup modules have been reduced as well. We were able to cut down the production costs for major OLEV components, the power supply, and the pickup system, and in turn, OLEV is one step closer to being commercialized.” If trains receive power wirelessly, the costs of railway wear and tear will be dramatically reduced. There will be no power rails, including electrical poles, required for the establishment of a railway system, and accordingly, lesser space will be needed. Tunnels will be built on a smaller scale, lowering construction costs. In addition, it will be helpful to overcome major obstacles that discourage the construction of high speed railway systems such as noise levels and problems in connecting pantograph and power rails. KAIST and KRRI plan to apply the wireless power transfer technology to trams in May and high speed trains in September.
2013.03.19
View 13476
Launched the Saudi Aramco-KAIST CO2 Management Center in Korea
KAIST and Saudi Aramco, a global energy and petrochemicals enterprise, signed on February 20, 2013 the Master Research and Collaboration Agreement (the Agreement) on joint collaborations in research and development of carbon management between the two entities. The Agreement was subsequently concluded upon the signing of the Memorandum of Understanding (MOU) between KAIST and Saudi Aramco, dated January 7th, 2013. In the Agreement, the two organizations specified terms and conditions necessary to conduct joint research projects and stipulated governing body for the operation of the Saudi Aramco-KAIST CO2 Management Center. KAIST and Saudi Aramco, a national oil company for Saudi Arabia, entered into the MOU, in which the two parties shared a common interest in addressing the issue of CO2 capture, CO2storage, CO2 avoidance using efficiency improvements, and converting CO2 into useful chemicals and other materials, and agreed to “create a major research center for CO2” in Korea. As envisioned by the MOU and its subsequent agreement, KAIST and Saudi Aramco decided to operate an interim office of the Saudi Aramco-KAIST CO2 Management Center at KAIST campus in Daejeon, Korea, pending the establishment of the research center. The full-fledged, independent research facility will be built at a location and during a period to be agreed between the two parties. Following the signing of the Agreement, there was a celebration event taken place, including a signboard hanging ceremony for the interim research office. A 10-member delegation from Saudi Aramco, which was headed by Vice President of Engineering Services Samir Al-Tubayyeb, Dr. Nam-Pyo Suh, former president of KAIST, Vice President of Research at KAIST Kyung-Wook Paik, and senior representatives from Korean oil and petrochemical companies such as S-Oil, Lotte Chemicals, SK Innovation, and STX attended the event. Kyung-Wook Paik, Vice President of Research at KAIST, said, “In order to help find solutions to carbon management, KAIST and Saudi Aramco will facilitate to exchange each party’s complementary technical expertise, gain insight into new research fields, and have access to key sources of talent, while promoting innovation for technology solutions and contributing to the lifelong learning agenda of both organizations.” Samir Al-Tubayyeb, Vice President of Engineering Services at Saudi Aramco, added that “As a world-leading oil and gas company, Saudi Aramco’s mission is to promote the continued use of safe, environmentally-friendly petroleum products with a vision to becoming a global leader in research and technology. Building a strong and cooperative relationship with KAIST in our endeavor to search for alternative ways to better utilization of fossil fuels will expedite the creation of opportunities to make the world environmentally safer and sustainable.” KAIST and Saudi Aramco will each chip in a maximum of USD 5 million annually for the establishment and operation of the Saudi Aramco-KAIST CO2 Management Center during the initial term of the Master Research and Collaboration Agreement, which starts in 2013 and continues through 2018.
2013.03.19
View 15035
KAIST and Saudi Aramco agreed to establish a joint CO2 research center in Korea
The Korea Advanced Institute of Science and Technology (KAIST) and Saudi Aramco, a global energy and petrochemicals enterprise, signed a memorandum of understanding (MOU) on January 6, 2013 in Dhahran, Saudi Arabia and pledged to jointly collaborate in research and development of innovative technologies and solutions to address the world"s energy challenges. Under the MOU, the two entities agreed to establish a research center, Saudi Aramco-KAIST CO2 Research Center, near KAIST"s main campus in Daejeon, Korea. The research center, to be jointly managed by KAIST and Saudi Aramco, will foster and facilitate research collaborations in areas such as tackling carbon dioxide (CO2) emissions by removal or capture of CO2, conversing CO2 into useful products, developing efficiency improvements in energy production, sharing carbon management technologies, establishing exchange programs, and conducting joint projects. According to Saudi Aramco, the company"s collaboration with KAIST is the first partnership established in Asia. Khalid A. Al-Falih, President and CEO of Saudi Aramco, said, "The CO2 Research Center represents a major step in Saudi Aramco"s research and technology strategy to partner with top global institutions to help address and find sustainable solutions to the world’s energy challenge both domestically and internationally."
2013.03.19
View 11077
KAIST Inaugurates Its 15th President
President Sung-Mo “Steve” Kang praised what KAIST has achieved as a powerful engine for the economic and industrial advancement of Korea over the past 41 years, while pledging to continue its endeavor “to go above and beyond its present accomplishments.” KAIST inaugurated its 15th president, Sung-Mo “Steve” Kang, on February 27, 2013, in a ceremony at the auditorium of its main campus in Daejeon, South Korea. President Kang delivered his inauguration speech to 1,000 distinguished guests from government and public offices and the nation’s science community, including Chairman Myung Oh of the KAIST Board of Trustees, Former Presidents of KAIST Soon-Dal Choi and Chang-Sun Hong, Former National Assembly Member Yong-Kyung Lee, and members of the university. In his speech, President Kang recalled that he had formed a strong bond with KAIST over many years, before assuming the presidency and extolled the university’s contribution to Korea’s current economic prowess. Referring to the “growing pains” that KAIST has experienced amid its successes, he vowed to unify the university community to take another leap forward: We must ease the pain through trust and consideration for one another and join in unity to take steps toward the brighter tomorrow of KAIST. I humbly seek your help and pledge to put forth my utmost effort as a servant and leader. Speaking of KAIST’s importance to the Korean nation, President Kang said, “Korea, as a nation lacking a deep pool of natural resources, must find innovative ways to compete globally to ensure the prosperity and well-being of its people.” He emphasized KAIST’s role as a catalyst to “lead the nation toward the frontiers of science and technology with fervor and responsibility.” In order to become a global leader in higher learning and contribute to the advancement of science and technology in Korea and beyond, President Kang said that KAIST must do well in five areas with letters matching those of its own acronym: Knowledge creation, Advancement on all fronts, Integrity, Sustainability, and Trust. In knowledge creation, the president pointed out the necessity of collaboration, student-centered and faculty-led research programs, and interdisciplinary research. For advancement on all fronts, he proposed redrafting KAIST’s future blueprint by consulting with all of its constituents and the Board of Trustees to improve the overall efficiency of the university. President Kang added that KAIST should uphold integrity in all research publications, financial management, and human relations to withstand unforeseen challenges and problems and that is should seek sustainable value for education and research, not becoming overly driven by short-term research goals. Last, he said that KAIST must be an institution trusted by the public and KAIST faculty, students, and staff. This culture of trust can be made possible, he added, when the members of the university do their best to create an environment of understanding and caring for each other. President Kang concluded his remarks by promising that he would always open his door and welcome anyone for visits, discussions, and sharing. Known as “Captain Smooth” for the well-rounded, warm, yet decisive leadership style that he showed during his chancellorship at the University of California, Merced, President Kang now pledges to guide KAIST to become better and stronger in the next four years. For a full transcript of the speech, download the PDF file below.
2013.03.13
View 8473
2013 Graduation Ceremony Held on February 22
KAIST held a graduation ceremony for the year 2013 at Ryu Keun-Chul Sports Complex on February 22nd. A total of 2,475 academic degrees were awarded this day, including 482 doctoral degrees, 1,153 master’s degrees, 838 bachelor’s degrees, and two honorary doctorates to Dr. Han Seung-Soo, a former prime minister of South Korea, and Lee Soo-young, the chairwoman of Kwang Won Industrial Co. Ltd. This commencement made KAIST to have turned out overall 46,117 talented graduates – 9,383 doctorates, 23,941 master’s degrees, and 12,793 bachelor’s degrees – to the fields of science and technology since its establishment in 1971. The Minister of Education and Science Technology Award, which is for the student receiving bachelor’s degree with the highest academic performance, was given to Seung-Uk Jang from the Department of Mathematical Sciences. In addition, the Chairman of the KAIST Board of Trustees Award was given to Chi-Heon Kwon from the Department of Chemistry, KAIST Presidential Award to Yong-Jin Park from the Department of Chemical and Biomolecular Engineering, President of Alumni Association Award to Bong-Soo Choi from the Department Electrical Engineering, and School Supporting Association’s Award to Bo-Kyung Kim from the Bio and Brain Engineering Department. “Climate changes due to humanity’s economic activities are threatening crucial resources such as water, food, and energy security,” said Former Prime Minister Han Seung-Soo, who received an honorary doctorate at the commencement ceremony. “Please try to solve the greatest issues that human society is facing,” he entreated in his congratulatory message. “Use the excellent education that you have received at KAIST wisely with good purpose and ethics,” also congratulated President Suh Nam-Pyo. “I hope the graduating students of KAIST to become global leaders in the near future,” he said to the graduates entering the society. “It was a great honor to contribute as the president of KAIST for almost 7 years, which has been the most challenging and worthwhile time in my life,” he delivered words of gratitude to all members of KAIST. “I appreciate everyone’s efforts for KAIST to develop so far.” President Suh completed his duty as the fourteenth president of KAIST with the ceremony and returned to the United States on the 25th.
2013.02.26
View 9891
A Substance with Amazingly Improved Efficiency of Capturing Carbon Dioxides Developed
From left to right: Prof.Ali Coskun, Prof. Cafer T. Yavuz and Prof. Yousung Jung - Selectivity of CO2 increased by 300 times in comparison to nitrogen, published in Nature Communications- KAIST EEWS graduate school’s joint research team led by Prof. Cafer T. Yavuz, Prof. Ali Coskun, and Prof. Yousung Jung has developed the world"s most efficient CO2 absorbent that has 300 times higher carbon dioxide selectivity in comparison to nitrogen. Recently, the importance of CCS* technology, which is about capturing, storing and treating carbon dioxides, has begun to emerge world-widely as a practical alternative for the response to climate change. * CCS : Carbon Capture and sequestration Current carbon dioxide capturing technologies are wet capturing using liquid absorbent, dry capturing using solid absorbent and separation-membrane capturing using a thin membrane like a film. For the places like power plant and forge, where the emission of carbon dioxides is huge, the main task is to maintain the capturing efficiency under extremely hot and humid conditions. The previously studied dry absorbents, such as MOF or zeolite, had the disadvantages of instability in moist conditions and expensive cost for synthesis. On the other hand, the research team"s newly discovered dry absorbent, named ‘Azo-COP’, can be synthesized without any expensive catalysts so the production cost is very low. It is also stable under hot and humid conditions. COP is a structure consisting of simple organic molecules combined into porous polymer and is the first dry carbon dioxide capturing material developed by this research team. The research team introduced an additional functional group called "Azo" to the substance, so that it can selectively capture carbon dioxides among the mixture of gas. Azo-COP, which includes ‘Azo’ functional group, is manufactured easily by using common synthesis methods, and impurities are removed simply by using cheap solvents like water and acetone instead of expensive catalysts. As a result, the manufacturing cost has lowered drastically. Especially, Azo-COP is combined with carbon dioxides by weak attraction force rather than chemical attraction so the recycling energy cost for the absorbent can be reduced innovatively, and it is expected to be used for capturing substances other than carbon dioxides in various areas as it is stable under extreme conditions even under 350 degrees Celsius. This research is supported by Korea Carbon Capture&Sequestration R&D Center(Head: Sangdo Park) and KAIST EEWS planning group. Prof. Cafer T. Yavuz and Prof. Ali Coskun said that “when Azo-COP is used for separation of CO2 and N2, the capturing efficiency has increased by hundred times.” He continued “This substance does not need any catalysts and has great chemical characteristics like water stability and structure stability so is expected to be used in various fields including carbon dioxides capturing” Meanwhile, this research is published in ‘Nature’s stablemate ‘Nature Communications’ on 15th of Jan.
2013.02.24
View 13270
Professor Hwang Kyu Young and Professor Yang Dong Yeol Receives Engineer of Korea Award
Emeritus Professor Hwang Kyu Young (Department of Computer Sciences) and Professor Yang Dong Yeol (Department of Mechanical Engineering) were named as the 2012 Engineer of Korea by the Ministry of Education, Science, and Technology and Korea Science Foundation. The Engineer of Korea Award is awarded biannually to scientists and engineers that have contributed to the development of Korea’s science and technology and national economy. Professor Hwang’s work with DBMS and close coupling architecture of information search and overall new theories and application technology development in the field of database system has aided the opening and expansion of IT software industry development and the advent of internet information culture era. Professor Yang is a word renowned scholar in the field of net shape manufacturing and is considered to have opened a new page in the field of nano-molding technique. In addition, Professor Eum Sang Il (Department of Mathematical Science) has been selected as the 2012 Young Scientist Award.
2013.01.22
View 12898
Professor Lee Jeong Yong Receives 2012 'KAISTian of the Year' Award
Professor Lee Jeong Yong (Department of Material Science and Engineering) received the 2012 ‘KAISTian of the Year’ Award. Professor Lee had successfully developed a technique that allowed the observation and analysis of liquid in atomic scale. The technique is expected to have great impact on nano-material synthesis in solution, explaining electrode and electrolyte reaction, liquid and catalysis reaction research, and etc. and was therefore named as the best experimental accomplishment in KAIST in 2012. Professor Lee and his team’s finding has been published in the April edition of Science magazine and has had attracted the attention of the world. In addition, BBC News, and Science & Environment reported on the findings as their respective top articles. The optical microscope is incapable of atomic scale observation and the electron microscopes are capable but because of the vacuum state all liquids undergo evaporation making it impossible to observe liquids in an atomic scale. Professor Lee’s team wrapped the liquid with a layer of grapheme to prevent evaporation and successfully observed real time the platinum growth process in solution. Professor Lee’s findings were introduced as an example of exemplar research case in the Presidential address for ‘Science Day’ in April.
2013.01.22
View 10123
KAIST Professors win 2012 Korea Engineering Award
Distinguished Professor Hwang Gyu Young (Department of Computer Science) and Professor Yang Dong Yol (Department of Mechanical Engineering) from KAIST received the 2012 ‘Korea Engineering Award’ hosted by the Ministry of Education, Science and Technology and the Korea Research Foundation. The ‘Korea Engineering Award’ is given biennially to researchers who have accomplished world class research and have contributed greatly to Korea’s development in the field of Science and Technology. The award started in 1994 and a total of 24 recipients were recognized in various fields such as electronics, mechanics, chemistry, construction, etc. The recipients of the award areawarded the Presidential award as well as 50million won as prize money. Professor Hwang was recognized for his research on DBMS close-coupling architecture as well as other new data base system theories, contributing to the development of the IT software industry in Korea. Professor Yang was praised for his work in precision shape creation and manufacturing, especially for his work in the nano-stereolithography process. In addition, Professor Oum Sang-il from the Deparment of Mathematical Science received the 2012 ‘Young Scientist Award’ hosted by the Ministry of Education, Science and Technology and the Korean Academy of Science and Technology. The ceremony for ‘Korea Engineering Award’ and the ‘Young Scientist Award’ was held in Seoul Press Center Press Club on the 21st of December.
2012.12.26
View 14639
Professor Hwang Gyu Young Elected as Chairman of IEEE TCDE.
Professor Hwang Gyu Young (Department of Computer Science) was elected as the Chairman of IEEE (Institute of Electrical and Electronics Engineers) TCDE (Technical Committee on Data Engineering). IEEE TCDE is one of the three academic organizations (including VLDB Endowment, ACM SIGMOD) and Professor Hwang is the first to be elected as Chairman from the Asia-Pacific region. Professor Hwang’s tenure begins on New Year’s Day for two years. IEEE TCDE holds the world’s most prestigious academic competition IEEE ICDE and hosts the Working Group and publishes the IEEE Data Engineering Bulletin.
2012.12.21
View 10822
KAIST shocks the world with its creativity
Researchers at KAIST yielded great results at the world’s leading international Human Computer Interaction Society. Professor Lee Gi Hyuk’s (Department of Computer Sciences) and Professor Bae Seok Hyung’ (Department of Industrial Design) respective teams received awards in two criteria in student innovation contest and was the only domestic university that presented their thesis at the ACM Symposium on User Interface Software. The ACM UIST holds a student innovation contest prior to its opening. This year’s topic was the pressure sensing multi touch pad of Synaptics and involved 27 prestigious universities including MIT and CMU. The KAIST team (Ki Son Joon Ph.D. candidate, Son Jeong Min M.A. candidate of Department of Computer Sciences and Woo Soo Jin M.A. candidate of Department of Industrial Design) designed a system that allows modulated control by attaching a simple structure to the pressure sensing multi touch pad. The second KAIST team (Huh Seong Guk Ph.D. candidate, Han Jae Hyun Ph.D. candidate, Koo Ji Sung Ph.D. candidate at the Department of Computer Sciences, and Choi Ha Yan M.A. candidate at Department of Industrial Design) designed a system that utilizes a highly elastic fiber to allow the sensing of lateral forces. They also created a slingshot game application which was the second most popular system. In the thesis session Professor Bae’s team (Lee DaWhee Ph.D. candidate, Son Kyung Hee Ph.D. candidate, Lee Joon Hyup M.A. candidate at Department of Industrial Design) presented a thesis that dealt with the technology that innovated the table pen for displays. The new ‘phantom pen’ solved the issue arising from the hiding effect of the pen’s contact point and the display error due to the thickness of the display. In addition the ‘phantom pen’ has the ability to show the same effects as crayons or markers in a digital environment.
2012.11.29
View 12140
<<
첫번째페이지
<
이전 페이지
21
22
23
24
25
26
27
28
29
30
>
다음 페이지
>>
마지막 페이지 50