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2019-06 19

[Academics][Researcher of the Month] Creating a Virtual Power Plant

With the upcoming Industry 4.0 and development of technology, the trend in manufacturing is to put an enhanced emphasis upon mass production. Both the academic field and industrial world are looking for effective solutions that can adjust to meet to the fast-changing industry in which a variety of products and a fast production process are becoming important issues. While most machinery and systems have become automated, the production system itself has become more complex and has problems that have yet to be solved. Professor Hong Seung-ho (Division of Electrical Engineering) has released a paper titled "A data mining-driven incentive-based demand response scheme for a virtual power plant" which focuses on solving such problems within the current manufacturing system. Hong has continuously focused on a new industrial manufacturing technique that would help operate a factory more effectively. The Cyber Physical System (CPS), which Hong is currently working on, is a system that can help such problems by realizing a more efficient production process. The CPS creates a digital twin, an identical imaginary model of an actual tangible product, by using the information within a computer. This digital twin allows the effective operation of a factory, as the machinery within the program is provided with the ability to autonomously communicate with each other based on issues such as space and active areas. This model shows the actual demonstration of a manufacturing system. The Cyber Physical System (CPS) creates a digital twin, which allows automated communication between such machinery. (Photo Courtesy of Hong) As the system designers, engineers, and supervisors are able to solve problems in a much easier manner, the whole manufacturing process will be greatly accelerated. The development of CPS will also allow greater efficiency in productivity and energy usage. During the operation process, the system keeps track of the data of operating assets, such as temperature and speed, while continuously analyzing and preserving a stable state for operation. Furthermore, the saved data can be used for supervisors to keep track of and analyze both current and potential breakdowns. “The CPS would be a great innovation for the current smart manufacturing system,” stated Hong. Yet, there are further steps to be taken before the actual application of the system. First, the standardization of machinery data is necessary. They need to develop a standard language in which the machines can communicate with each other, to work alongside standardized information and communications technology (ICT) and information transmission technologies. The machinery also requires artificial technology to be applied in order to realize the overall system. Hong predicted the year 2035 for a complete smart manufacturing system, and 2045 for it to be practically applied within Korea. Professor Hong Seung-ho (Division of Electrical Engineering) predicted that the smart manufacturing system would be complete by 2035, and applied in Korea by 2045. As for last words, Hong expressed his hopes for Hanyang students to also contribute to future innovative techniques. He maintained that “Steve Jobs is often regarded as a figure of innovation. I hope that the students can also develop their creative thoughts and put an effort towards realizing such innovative ideas.” Hong concluded by explaining that in order to do so it is important for students to start thinking of even the smallest innovative ideas that can actually change the world. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Lee Hyeon-seon

2019-04 30

[Academics][Researcher of the Month] Hedging Deep Features for Visual Tracking

Professor Lim Jong-woo (Division of Computer Science and Engineering) has recently published his thesis "Hedging Deep Features for Visual Tracking" in IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI). The thesis was mainly about discovering an algorithm that enables visual tracking of objects' features within a video through an artificial neural network. Professor Lim Jong-woo (Division of Computer Science and Engineering) wrote a thesis on discovering an algorithm that enables the visual tracking of the features of objects within a video through an artificial neural network. Convolutional Neural Network (CNN) According to Lim, the studies of Convolutional Neural Networks (CNN) have led to the development of the field of computer vision and deep learning by producing continuous results over the past 10 years. A CNN refers to a network that delivers information about certain objects through the analysis of data produced within each layer of information. The former part of the network provides information about the location of a certain object, whereas the latter mainly handles data related to the type or meaning of the object. In order to accurately position or track an object within a video, both types of information are required, which leads to the need for technology that can successfully fuse the provided information within each layer. Lim’s recent research enables this particular fusion of the various layers of information by applying a technology called hedging, which was derived from machine learning methods. Whenever a new frame is input, the location of the object is traced based upon a corrective filter that collects the information within the different layers of the CNN. This "history sensitive hedging" method, which was newly introduced in Lim’s studies, recalls every result of each layer, enabling the selection of the most relevant layer in relation to the present frame. This hedging method has allowed more efficient and productive results compared to the conventional methods of the visual tracking of objects. The overall visual tracking process that occurs within a newly input frame, using the hedging technology introduced by Lim (Photo courtesy of Lim) The significance of the research Lim’s recent thesis is an extension of his past research "Hedged Deep Thinking," published in 2016 in the IEEE Conference on Computer Vision and Pattern Recognition (CVPR), which focused on applying the visual features in deep learning to the procedures for tracking objects. The conventional method was simply using all the positional information derived from each layer of the CNN, yet the CVPR thesis introduced an algorithm that selects only the necessary information through a hedging method. “My latest thesis is one that expands such studies by applying a Siamese network that further distinguishes the object of scrutiny and a cumulative regret model that reflects the former weight measures within previous frames into the most present one,” explained Lim. A Scale search step was also added in order to prepare for situations in which the size of the object changes. Lim stated that his newly presented algorithm has allowed a further step within the field of visual tracking technology by producing superior results compared to the conventional State-of-the-art algorithm. For an easier understanding, Lim pointed out the current CCTV business. Enabling the visual tracking of certain objects within a video, which includes both organic and inorganic materials, Lim’s newly introduced algorithm allows this process to be conducted in a more intelligent manner by efficiently selecting only the necessary features within each layer of the CNN. As an example, Lim illustrated a potential use of this new technology by using the CCTV monitoring process at airports. His new technology would make the process of identifying and tracking suspicious figures easier. Automatic driving and action cameras were also other fields that Lim presented as examples the technology could be applied to. Lim is explaining the significance of his newly published thesis and how it can be applied to more practical fields. Future plans Lim shared his future plans of conducting research on the multiplex visual tracking technology that allows the tracking process to be widened towards multiple objects, which is an expansion of the current visual tracking technology which mainly focuses on tracking a single object. Furthermore, he also stated how he and his laboratory students are working on the image-based attitude estimation and three dimensional restoration technologies, which can be related to the fields of automatic driving, AR/VR, and even robots. As for the last comments, Lim stated that many professors and students of the Division of Computer Science and Engineering are currently conducting research on artificial intelligence and its related fields such as computer vision and data mining. “I hope that such research aids in the needed progress in this field, and that the professors and students are able to find various opportunities of acquiring the professional knowledge to develop their strengths and abilities,” finished Lim. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Kim Joo-eun

2019-03 18

[Academics]Protein Supplementation Improves Physical Performance In Undernourished Elderly Subjects

The existing theory towards the physical performance of the elderly was that decrepitude could only be tackled by providing nutrition alongside a certain level of physical exercise. Professor Park Yong-soon (Department of Food and Nutrition), however, has managed to go against this existing belief, proving that protein supplementation itself, irrelevant to any levels of physical exercise, can help overcome decrepitude by preventing muscle loss of the undernourished and frail elderly population. With her recent research even being published in the renowned academic journal, American Journal of Clinical Nutrition (AJCN), Park has been recognized for her breakthrough in tackling the long problems associated with decrepitude. Professor Park Yong-soon (Department of Food and Nutrition) explains her recent research on the impact of protein supplementation and the physical abilities of the undernourished elderly. Having selected 120 elderly subjects, Park provided them with 0.8, 1.2, and 1.5 grams of protein on a daily basis for 12 weeks. The protein was provided in the form of powder dissolved in a corn silk tea solution. The protein powder was carefully selected, due to the weakened digestive system of the seniors and, thus, it was essential that the powder had a high purity of protein in order to ensure that the subjects took in the required amount of additional nutrition. Furthermore, Park also implemented strict dietary control, keeping track of the total amount of nutrition that her subjects were ingesting daily. The subjects were also carefully selected by Park. Focusing only on those aged between 75 and 85, the subjects all had to pass a certain "Power Test," which evaluated their physical abilities such as the time it takes them to walk four meters and how much time it takes them to sit down and stand up. Selecting 120 out of a total screening of 400, Park closely examined the changes in physical abilities among the selected subjects, being able to successfully prove that the supplementation of protein itself does have a positive impact on the physical abilities of the frail elderly. The diagrams show how the subjects were randomly assigned protein supplements during the research period. (Photo Courtesy of Park) According to Park, as the research was conducted in the form of a clinical demonstration, there were many hardships that had to be overcome. A basic clinical demonstration included observing the process of giving selected subjects a certain substance and analyzing the results. However, as it is literally impossible to have total control over the subjects, unexpected variables occur, especially with elderly subjects being relatively more vulnerable to external factors. “Many of the subjects had to quit due to sudden accidents or illnesses. We also had to deliver the products to them door to door in order to prevent any mistakes,” explained Park. Although Park has proven the positive impacts of protein supplements upon the frail elderly, she stated that she is now working on finding the most ideal amount, as the current research only provided fixed amounts of 0.8, 1.2, and 1.5 grams of protein for its subjects. In addition to her further research, Park also showed her hopes of changing the current Body Mass Index (BMI) standards, asserting that it is debatable whether the elderly should have the same standards as younger adults. She explained that standards for the elderly should be changed, as a certain amount of fat has been proven to be healthier for them. As a nutrionist, Park hopes to further extend her research to find the ideal protein supplement amount and to revise the current BMI standards. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Park Guen-hyung

2019-01 14

[Academics]Performance of Stock Price with Changes in SRI Governance Index

Professor Lee Chang-won (School of Business) recently presented his study on the performance of stock price with changes in socially responsible investment (SRI) governance index. Mainly looking at the different levels of performance that various corporations are achieving depending on their SRI, Lee has managed to publish his studies in the academic journal, "Corporate Social Responsibility and Environmental Management." According to Lee, while the performance of a corporation was evaluated only on its actual profit in the past, the importance of fulfilling its social responsibility is gaining weight in its evaluation in order to achieve sustainable growth nowadays. With a trend of studying how to reflect social responsibility within the actual performance of a company, Lee has managed to find the correlations between the stock price of a corporation, which represents its performance, and its inclusion within the SRI governance index. Professor Lee Chang-won (School of Business) recently presented his study on the performance of stock price with changes in SRI governance index, finding the correlation of how corporations within the index showed higher levels of performance both in the short and long term. “It is those that are included in this SRI governance index that have managed to show a higher performance both in the short and long term,” stated Lee. Having to satisfy the various stakeholders within the company, it is mainly those that have managed to conduct such social actions that have seen an actual rise of their stock price, or in other words, shown high levels of performance. This is especially applicable to global corporations, as they have to satisfy the different levels of social actions that their more varied stakeholders require. Socially responsible investment (SRI) It was explained by Lee that the social responsibility of corporations varies across a number of fields, including those of environmental, economic and even those related to the governance structure of such companies. Presenting an example of environmental responsibility, he explained how corporations within the index focus upon issues, both internally and externally. Internally, the working environments of the workers are improved, whereas externally, environmental problems such as air pollution are tackled by the company. The importance of such actions is becoming enhanced, especially when related to the sustainable growth of a corporation. Additional to the traditional financial index, the SRI is also becoming a significant metric for success. “It can be compared to today’s students. They are not only required to simply study hard during their school years but also to become skilled in order to adapt and succeed in the contemporary society. The same goes for companies, as they have to do more than simply make profit,” explained Lee. Lee explained how the inclusion of the SRI governance index has now become an important metric for the performance of corporations and their sustainable growth. The research and its future With the importance of social responsibility for corporations gaining light, Lee believes that it is the highest level of management that should be mostly focused towards this trend. In order to become a corporation that successfully conducts business on the international level, it is crucial to be included within the SRI index and fulfill the levels of social responsibility that is being required in the current industry. Lee started his research in order to prove this correlation and arouse the attentions of domestic corporations, which put a heavy emphasis upon ‘owner leadership.’ Using the traditional event history analysis method, Lee focused upon the actual factors that had an impact upon a corporations’ stock price and compared the performance of those that are either included or excluded within the SRI governance index from 2003 to 2012. He was able to conclude the significance of the inclusion within the SRI index as being crucial, especially within the global business environment. This is due to the fact that it is not only the developed markets, but also the markets of developing countries that are placing a higher emphasis upon social responsibility. Based on his research, Lee showed his hopes towards corporations showing a higher interest in social responsibility, becoming a company that goes from ‘Good to Great’ and that can show actual contributions towards a healthier society. He also added that the students of Hanyang should also become figures that are able to acknowledge and fulfill the responsibilities that the society requires, being able to carry out the school philosophy of ‘Love in Deed’ when they become the true leaders of society in the future. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Park Guen-hyung

2018-12 05

[Academics][Excellent R&D] Promoting the Global Competence of Domestic Businesses

The Korea Institute of Sustainable Economy (KISE) is one of the 18 surviving teams of the Social Science Korea (SSK) business, supervised by the National Research Foundation of Korea (NRF). Being evaluated on mainly three stages, KISE has managed to surpass the former two evaluation processes by currently focusing its research upon enhancing the global competence of domestic businesses, especially from the viewpoint of distribution systems. The Social Science Korea (SSK) business refers to a research program funded by the NRF, which was first started in 2010 with the purpose of promoting research institutions that conduct research activities in the field of humanities and social science on an international basis. Whereas most research programs of the social science field are funded on a two to three year period, the SSK is a more long-term one which was targeted with ten years of research, developing into three stages: small, medium, and large-sized projects. Only the teams that pass the evaluations of the NRF upon their progress on the former stages are able to move on to the projects of the later phases. With an initial 90 teams being selected out of the 500 that applied for the small-sized studies, only 45 were able to move on to the medium-sized projects. Once again, the number was halved to 20 when advancing on to the final stage, with the current surviving teams counting up to only 18. KISE In this sense, KISE has made great progress on not only the former two phases of research, but also its current large-sized project. Professor Kim Bo-young (School of Business), the director of KISE, explained the progress that KISE has gone through the past eight years of research since 2010. Professor Kim Bo-young (School of Business), the director of the Korea Institute of Sustainable Economy (KISE), is explaining the research progress that KISE has gone through since 2010. Small-sized project When first starting the SSK project, KISE first focused upon an agenda that had both a social impact and practical implications. With a large emphasis being put on the Free Trade Agreements (FTA), especially upon the food industry at the time, KISE targeted their research towards the sustainable growth of ‘Food Security,’ ‘Food Safety,’ and ‘Global Branding Strategies.’ While giving a main focus upon China, as a major trade partner, KISE studied and compared the food safety management system of the two countries. Also giving light to the distributional process of the food industry, KISE conducted research on the strategies of marketing and positioning that the domestic businesses should implement when exporting food. KISE studied the actual products of Korea and China, and the strategies that would help them gain competence in the global market and maintain a global brand image. With the studies mainly focused upon China, during this stage, Kim and her team formed a global network with Chinese research institutions, while holding various symposiums on the subject. Medium-sized project Moving on to the medium-sized project in 2013, KISE targeted their focus more to the open global market in order to meet the goals of sustainable development. During this stage, KISE also collaborated with the Climate Change Center of Konkuk University, in order to study the steady supply and growth of food during extreme weather conditions. The studies also became more diversified with focusing on mainly four points within the global market. With health products gaining more popularity in the global markets and the industry also fiercely enhancing, KISE studied how Korean health products, such as ‘Ginseng,’ should promote themselves within this particular market. Unlike the small-sized stage, the comparatives were extended from China to other countries including the U.S., Europe, and Japan. The international consuming patterns and how Korean industries should position themselves within such global trends was also a main study of this stage. Risk communication models were also researched and compared on a global basis. With various countries all having their own model, the advantages and disadvantages of each model were given a thorough research. Cooperation with the Ministry of Food and Drug Safety (MOFD) was made in order to find the ideal model of handling food-related crisis. The last of the four main points, the actual infrastructure of the distribution process, was not put upon full focus during the medium phase, but was given more light in the later large-sized project. Large-sized project (Current) When entering the large-sized phase in 2016, the distribution system went through a great change under the fourth industrial revolution. For this reason, the infrastructure of the distribution process, from the former stage, became the main research in this large phase. With offline and online channels becoming united, the distribution system is going through an innovative process in which the consuming patterns are also greatly changing. Being in an early stage of adaption of such systems, KISE targeted its research towards how both consumers and industries would react to this major change. Kim is explaining how the use of big-data will be an important aspect in the new distributional system of the fourth industrial revolution. How this innovative change is being accepted in other comparative countries was a start of this particular research. Collaborating with the Japanese company ‘MUJI’ and having access to their big data on consumption patterns, KISE is further targeting their research beyond the food industry into other various consumer goods and how the domestic industries should position themselves in this rapidly changing system. With the access of big data allowing KISE to extend and deepen their research, there are still some remaining goals of the institution. According to Kim, studying the practical implications that the innovative distribution system has upon market competence, the rapidly changing consumer patterns, and the global strategies that domestic businesses should implement within this new system to maintain their global competence and brand image are the main remaining tasks that KISE should conclude during this large stage. With around two years left for the SSK project, Kim asserted that this does not designate an end to the current research that KISE is conducting. Although the SSK project did indicate a start for KISE, it does not necessarily correspond to an end. Kim also added that there will be further tasks and research that she and KISE should conduct in helping promote the global competence of domestic businesses, especially in the forms of sustainable growth. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Park Guen-hyung

2018-10 08

[Academics][Excellent R&D] The Korean Imitation Game

Until just several decades ago, warfare was in the form of military, unlike today's contemporary world where the international society puts heavy emphasis on global peace. This, in other words, means the use of military force has become limited and instead, the role of information warfare has now become a crucial factor in defedning a country's existence. Professor Yoon Dong-weon (Department of Electronic Engineering) and the Signal Intelligence Research Center (SIRC) are now in charge of the frontline of signal intelligence alongside the Defense Acquisition Program Administration (DAPA). The Signal Intelligence Research Center (SIRC) A specialized research center refers to those who have been appointed in grafting the high leveled technology of the private sector into technology that is developed and used for the purpose of national defense. It is DAPA, which designates the specialized research centers, appointing the SIRC as the one responsible for signal intelligence until 2020. Being a six-year project, and being funded with 12.5 billion won in total, the SIRC is the first specialized research center to have a recurring demand troop. (From left) Professor Yoon Dong-weon (Department of Electronic Engineering) and Ahn Seong-jin (Department of Electronic Engineering, Master's Degree) are analyzing the signal codes. The center mainly consists of four laboratories, with each serving its own purpose: signal collection technology, signal processing technology, voice information technology, and code reconstruction technology. With Hanyang University taking the lead in the overall research, 17 schools and 34 professors in total are currently participating. Being a six-year project divided into mainly two stages, the center has successfully completed the first part of research and has moved on to the second stage in 2018. The Importance of Signal Intelligence (SIGINT) According to Yoon, who is the current director of the SIRC, one the most fundamental concepts of information warfare is signal intelligence, which is intelligence-gathering by the interception of signals. National intelligence is mainly divided in to two categories, which are tactical intelligence and strategic intelligence. Tactical intelligence refers to short-term information, whereas strategic intelligence focuses more upon long-term information. From this perspective, strategic intelligence is a comprehensive national intelligence that has to be studied and researched persistently. Consisting of imagery intelligence (IMINT), human intelligence (HUMINT), open-source intelligence (OSINT), and signal intelligence (SIGINT), it is SIGINT that is being mainly focused upon in the contemporary society and has to be studied in order to preserve the existence of a nation from a strategic level. Yoon is explaining the importance of signal intelligence in the contemporary society and how it should be persistently studied in order to defend the nation's existence. “Signal intelligence is once again divided into communication intelligence (COMINT), electronic intelligence (ELINT), and foreign instrumental signal intelligence (FISINT). Out of the three, it is communication intelligence that the research center is mainly focusing upon. It is easier if one thinks of the movie ‘The Imitation Game (Morten Tyldum, 2014)’ and how signal intelligence is used in defending the existence of the country,” explained Yoon. Yoon also mentioned that although we currently live in an era of peace, it is important to keep track of potential threats and consistently prepare ourselves, given that we are surrounded by countries that have strong abilities of signal intelligence. “SIRC will always lead an edge in defending national security and signal intelligence,” ended Yoon determinedly. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Lee Jin-myung

2018-09 17

[Academics]The Development of Multi-Sensory Exhibitions

Professor Ryu Ho-kyung (Department of Arts and Technology) is currently working on a technological program that allows the multi-sensory exhibition in places such as art, science, and historical museums. Having planned the project for three and a half years, it has been roughly six months since Ryu and his team initiated the project. Collaborating with the Gwacheon National Science Museum (GNSM), the team is planning to exhibit its first results in September of 2019. From left, Jung Dong-hoon, Professor Ryu Ho-kyung, Jin Sang-min, and Lee Seung-jung are working to develop a multi-sensed exhibition, which allows spectators to experience the exhibition not only in a visual sense, but also in audible and tacticle senses. The term 'multi-sensory exhibition' refers to an exhibition that does not provide only visual experience, but also allows its spectators to hear and feel the displayed works. Formed with four research students, Jin Sang-min, Lee Seung-jung, Jung Dong-hoon, Min Bo-kun (Department of Arts and Technology, Master’s Program), and two professors, Ryu and Kim Ji-eun (Department of Technology and Innovation Movement), the team has divided its research plans into four stages. The first stage is to develope a framework and prototype for the multi-sensory exhibition, followed by the next stage of collecting and analyzing the data based on the reactions of spectators. Then, applying an actual multi-sensory exhibition at the GNSM is in order, after which the final stage of developing a guideline for applications to other site operations comes. Proceeding with the early stage of development, the team is currently focusing on developing a prototype of a multi-sensory exhibition, which requires the convergence of various fields of technology. “Psychological elements, design elements, and engineering design are the three main elements necessary for the project,” explained Ryu. With each member of the team having his or her own specialty, they have managed to incorporate three types of technology to actualize the different senses of spectators. As for the visual aspect, the team is planning to shoot AI (artificial intelligence) visions upon a half-transparent screen, which would play 3D vision throughout the exhibition. According to Jung, it would enable spectators to interact with the exhibited materials, similar to the movie ‘Night at the Museum (2011).’ As for hearing sense, directional speakers are under development. The speakers can only be heard in the area in which they are targeted, which prevents the whole museum from being sabotaged by multiple sources of sound. Ryu gave an example of how spectators would be able to hear the sound of a crying dinosaur only in the front of the exhibited model, once the speakers are applied. Lastly, for tactile sense, vibration mats will be applied, which are sound-induced vibration. These mats are designed to react to the vibration of sound, which enables them to be activated in accordance with the directional speakers and provide tactile aspects. From left, Jin, Lee, and Jung are explaining the technologies that are applied in the development of multi-sensory exhibitions. This project has its significance in that it has the main purpose of ‘returning to the public.’ Applying technology in an area that is closely related to and enjoyed by the public was the key importance for Ryu. This whole project allows the public, especially students, to have an improved experience at museums. Once applied to all museums, multi-sensory exhibitions would allow the spectators to become investigators that actually interact with the displayed materials. For this reason, Ryu and his team are also focusing on lowering the price exhibitions, so that they can be applied to all museums at an affordable cost. “Many students these days tend to think of research and development as something that is distant and unapproachable. However, research is something that is close to our everyday lives and can be used for solving real world problems,” maintained Ryu. He also added that those who would like to participate in this project should contact Jung by e-mail (Rapido300@gmail.com). Although still in its initial stage, there is no doubt that multi-sensory exhibitions would provide a completely new experience for museum-goers. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Kang Cho-hyun

2018-07 30

[Academics][Researcher of the Month] Observation of Unique Properties of Anti-PT-Symmetric Systems

Professor Song Seok-ho (Department of Physics) has recently announced his research on the observation of an Anti-Parity-Time (APT)-Symmetric exceptional point and energy-difference conserving dynamics in electric circuit resonators. When dividing an electric circuit in half, the two parts show a symmetric stream in both time and space. This is referred to as Parity-Time (PT) Symmetry, which enables electricity to flow in the same stream in both directions inside an electric circuit. By "breaking" the unidirectional converter, the symmetric stream of the forward and backward propagation differs, and the PT-Symmetric form is broken. This picture shows the breaking of the Parity-Time (PT) - symmetric form and how the flow of light changes. By breaking the symmetric middle part, the forms of foward and backward propagation differ, which allows for the creation of diodes. (Photo courtesy of Song) Breaking the PT-Symmetric form allows for the creation of diodes which are semiconductor devices that allow electricity to flow only in one direction and prevent any form of backward propagation. Being a key element of the flow of electricity within an electric circuit, the creation of photodiodes has been a long-term goal in the field of nanophotonics. Based upon the idea of substituting electricity with light, which would allow electric devices to be used with higher speed and energy efficiency, nanophotonics have long been troubled with a loss of energy due to the absence of diodes which allow the efficient flow of energy. Thus, Song’s current research of creating diodes through the "breaking" of PT Symmetries has significance, as it may provide a foothold for the creation of photodiodes. Song has verified his research by successfully breaking symmetries within electric circuits formed with resistance-electric condensers. The experimental process was made as simple as possible based upon the professor’s belief that easy verification leads to easy commercialization. “It is the process of thinking out ideas that should be given effort, whereas the experimental process should be done with ease,” explained Song. This can be seen in the fact that only simple devices with educational purposes were used in the verification of this research. Professor Song Seok-ho shared his research philosophy of the making process which should receive the bulk of time and effort. On the other hand, he mentioned that the experimental process should be conducted as simply as possible, as simple verification leads to simple commercialization. When asked of his future plans, Song explained how he has managed to break through one mere field of nanophotonics. He also maintained that “there are so many fields to overcome. By applying concepts to each field, breaking through the current limitations of physics is my next goal.” Succeeding with the observation of anti-PT-symmetries, it does not seem like it will be long before Song provides another foothold towards a novel breakthrough in the field of nanophotonics. Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Choi Min-ju

2018-06 18

[Academics][Excellent R&D] Organic-Inorganic Hybrid Multi Layers

Barrier films that have the ability to block moisture and aerial gas have long been a concern of the packaging industry, especially in the display business. The penetration of such substances leads to a degradation of display materials to protect, which is the main reason why barrier films are utilized. Song Tae-seob (Department of Energy Engineering) has provided a solution to this troublesome dilemma, by proposing the use of using organic-inorganic hybrid multi layers. The use of inorganic materials when making a barrier film is highly effective in blocking the penetration of other substances, but the heat treatment and the use of the equipment comes with a high price tag. On the other hand, organic materials have an easier production process, yet are relatively more vulnerable to penetration by moisture and air. Thus, Song has converged these two materials, which would result in a barrier film higher in both ability and cost efficiency. Song Tae-seob (Department of Energy Engineering) explained how converging organic and inorganic materials can result in the production of a barrier with higher abilities and improved cost efficiency. According to Song, there have been techniques to combine the two materials, but they have not yet been applied to the production of barrier films. Thus, the remaining task for Song was to focus upon making a convergence of the two materials and managing to evenly spread and disperse the inorganic material within the organic solution. "Inorganic materials have a tendency to crumple down within an organic solution. Therefore, finding a way to alleviate this mass and allow them to spread evenly within the solution is a key factor to our research," explained Song. Being a professor in the Department of Energy Engineering and primarily studying batteries, Song has had hardships in this relatively unfamiliar field of research. As it is applying an already existing technique, Song and his laboratory members have focused on developing their technologies while avoiding existing patents. Having the need to develop a product from a new perspective with a novel concept, while diverting from current technologies, Song had another barrier to overcome. However, once such hardships are overcome and the current research is fully conducted, the outcomes will be significant. By localizing the novel barrier film technique, the domestic industry will prosper economically. “The domestic display business will benefit from being supplied with products that are more efficient in both cost and capacity. Furthermore, the barriers can also be extended to various businesses such as solar cells, which have also been troubled with moisture and air penetration," commented Song. Song and his students showing their strong will to develop an organic-inorganic hybrid material barrier. From the left, Lee Kang-chun (Energy Engineering, PhD Degree), Song, Jo Seong-han, Kim Gae-un, and Park Sang-woo (Energy Engineering, Master's program). Choi Seo-yong tjdyd1@daum.net Photos by Choi Min-ju

2018-04 30

[Academics][Researcher of the Month] Applying Terahertz to Weld-Line Detection

The weld-line among moulding injected plastic products have long presented a challenge in the production of plastic. Destruction of a specific plastic product has been considered necessary in the process of examining any existing weld-lines within the material. However, based on his newly released paper "Terahertz time-domain spectroscopy of weld-line defects formed during an injection moulding process," Kim Hak-sung (Mechanical Engineering) has coined the concept of applying terahertz radiation in this examination process. Based upon the terahertz time domain spectroscopy (THz-TDS), Kim has introduced a novel method of detecting weld-lines among moulding injected plastic products in a nondestructive manner. The THz-TDS technique In order to understand the THz-TDS system, one must become familiar with the actual concept of terahertz. Terahertz refers to a frequency unit of electromagnetic waves, counting up to one trillion cycles per second. Its long microwaves and wavelengths provide it a high permeability which allows terahertz to surpass materials other than metal. This high permeability leads to the THz-TDS, a spectroscopic technique in which the properties of matter are examined through different phases of terahertz radiation. In short, when shot at a specific target, the phases of terahertz radiation differ while surpassing different materials. Professor Kim Hak-sung (Mechanical Engineering) explained the benefits of terahertz radiation and how it can be applied to more practical fields. Although THz-TDS was an already-existing technique, it was Kim who applied it to the more practical field of finding weld-lines among plastic products. Weld-lines are lines that occur around areas where two flow fronts meet, yet are unstably "welded" together in the moulding process. These weld-lines cause weak areas among the moulded part, which may lead to a breakage of the product when the part is under pressure. Until now, the inevitable destruction of the whole product has been regarded as the only method of scrutinizing the existence of weld-lines. However, Kim has introduced a new method, which allows the weld-lines to be detected without breakage. Applying THz-TDS to weld-line detection As mentioned above, different phases of terahertz radiation occur when surpassing different materials. This variation of phases allows one to determine the specific material that the terahertz radiation is currently transcending through. Thus, when shooting terahertz radiation at moulding injected plastic products, the distinctions that occur among phases would be the areas where weld-lines, different layers than other parts of the product, are detected. This would eliminate the necessity of the current destructive weld-line determination process, as simply shooting terahertz radiation at the plastic products enables the investigation method to be possible without any force input. The phases of terahertz radiation differ according to the existence of weld-lines, which allows the detection of such weld-lines within plastic products. (Photo courtesy of Kim) Kim implemented a scanning method when conducting experiments to prove his theory. While attaching a mirror to the terahertz radiation, he moved the specimens according to their reflections. In order to make the reflections happen, the mirror was given a metalized-coating, considering the fact that terahertz surpasses all materials but metal. He managed to make a reflective-equipment that made the reflections occur on a much faster period, which allowed him to gather more results in a shorter time. According to Kim, the equipment is in its initial stage, yet developments are still being made towards totally eliminating minor errors. Hardships and future plans Despite achieving striking results, Kim also had hardships while conducting his research. Kim is a professor in the department of mechanical engineering, whereas terahertz research is related to the field of electronic engineering. Conducting research in a totally different field irrelevant to his major resulted in Kim having to look into two completely distinctive areas. However, he continued his research with only his students, without engaging in any form of joint research with others from departments in more closely-related fields. Oh Gyung-hwan, one of Kim's student assistants and co-leaders of this research, and Kim (left and right) commented on the importance of one finding his or her own reasons for conducting research and remarked that they want to help students find such causes. Such thought may result from Kim’s belief that research must be conducted in a positive manner. Kim mentioned, “I want my students to find their own reasons of pursuing specific research, while being proud of their achievements at the same time." He also added that this research was also conducted worldwide, and hence, his students should be proud of the significant results their global research. As for his future plans, Kim declaimed, “Despite my hardships in this study, I would like to do more research in a variety of other fields, while maintaining a firm stance within my major of mechanical engineering.” Choi Seo-yong tjdyd1@hanyang.ac.kr Photos by Choi Min-ju