• The Journal of Korean Institute of Information Technology
• /
• v.15 no.12
• /
• pp.181-188
• /
• 2017

As a population of leisure activities grows and diversifies, there is a great demand for portable and environment-friendly power generation systems. A small wind power generation system is emerging as a suitable power generation equipment to meet these needs. The most important thing when developing a small portable wind turbine is to reduce the weight of the generator and increase the efficiency. The existing 300W wind turbine generator weighs about 10kg, which is heavy to carry. Therefore, a new generator weighing less than 4kg to make it easy to carry with high efficiency has been developed. In addition, considering complicated characteristics of wind volume and topography of Korea, a small wind turbine that can be used in urban and rural areas individually was constructed. Through basic designing and optimization, the lightweight and efficient generator was manufactured. It is a 300W wind turbine designed and fabricated with reduced weight as a prototype. The average output voltage of the generator was 24.7V at 900rpm no-load test. On a load test with the average line voltage 36.8V and the average phase current 2.62A, when the mechanical input was 339.84W, an average voltage output of the generator was measured as 289.5W with efficiency of 85.18%. The generator weight was 3.84kg.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.2
• /
• pp.469-480
• /
• 2019

The purpose of this study is to enhance the cultural heritage value of the Juk-Bang-Ryeum (Bamboo Weir) and prove the originality through the review of historical literature. The main industry of Korean was agriculture and fishery from ancient. In the ancient, fishery instruments are not enough due to the lack of fishing technology. The Juk-Bang-Ryeum was considered as important national resources and asset. It give us many implications about the wisdom of our ancestors because of it's scientific principle of the structure. It is surely a cultural heritage to preserve in the future because it is considered as important community asset as well as more natural and environment oriented fishing method. In the literature, the origin of 'Juk-Bang-Ryeum' can be found as 'Eo-Ryang' or 'Bang-Ryeum'. The records on this terminology go back to the Corea Dynasty, but their documentary records are rare, and most of them are records of the Chosun Dynasty. In this study, we surveyed mainly the literature records about the southern coast region in the period of Chosun Dynasty. This study contributes for preserving the cultural assets of our ancestors who pursued eco-friendly fishery method, and it is also of great significance to produce objective data based on records for the registration of the World Record Heritage.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.437-445
• /
• 2018

IMO (International Maritime Organization) has been strengthening the regulations of ship emission gas such as sulfur oxides (SOX), nitrogen oxides (NOX) and carbon dioxides (CO2) to protect the marine environment. Especially, ECA (Emission Control Area) has been set and operated in the USA and US. As a countermeasure against these environmental regulations, the demand for environmentally, friendly and highly efficient vessels has led to a growing interest in technology related research with respect to electric propulsion systems capable of reducing exhaust gas. Container ships were excluded from the application coverage of the electric propulsion systems for reasons of operation at economical speed. However, in the future, the need for electric propulsion system is expected to rise, because it is easy to monitor and control so that it can be an applicate to smart ship which are represented by fourth industrial revolution technology. In this study, research was carried out to design a generator and battery capacity through the load analysis of the 6,800TEU container ship to apply the electric propulsion system of the container ship. A capacity design based on the load analysis has an advantage that the generator can be operated in a high efficiency section through the load distribution control using the battery.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.1
• /
• pp.165-173
• /
• 2019

Hydrazine[$N_2H_4$] is a typical propellant for a rocket fuel in the field of aerospace. Since it is very toxic and harmful to the environment, various environmentally-friendly propellants have been developed. In this study, relatively a safe propellant, hydroxylammonium nitrate[$NH_3OHNO_3$], was prepared via a neutralization reaction of hydroxylamine[$NH_2OH$] and nitric acid[$HNO_3$]. FT-IR was used to analyze the chemical composition, chemical structure and functional groups of HAN. Thermogravimetric analysis showed the decomposition temperature of HAN. Ion chromatography was also used to evaluate the content of nitrate ions. It was proved that the peaks of FT-IR at $3161cm^{-1}$ and $1324cm^{-1}$ indicates the functionalities of N-H and N-O present in HAN. The decomposition temperature of HAN synthesized at pH 5 to 7 was $120-140^{\circ}C$, and pH 8 resulted in higher decomposition temperature than $140^{\circ}C$. Meanwhile, the sample obtained from pH 6-7 showed the concentration of nitric acid ion with 70%.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.27 no.3
• /
• pp.149-158
• /
• 2021

Advances in food packaging play an important role in keeping food manufacturing and food supply safe. Food packaging facilitates the storage, handling, transportation and preservation of food, and also contributes to the minimization of food waste. On the other hand, food packaging materials have high production volumes, short usage times, and accelerate the occurrence of environmental problems related to waste. The circular economy has already been introduced to pursue sustainability through resource conservation and recycling, and to reduce waste and carbon emissions. By activating an eco-friendly economic system that minimizes resource depletion and environmental pollution, reducing, reusing, recycling and redesigning the goals of the circular economy will reduce the impact of food packaging on the environment. This review focused on the safety aspects of recycled food packaging as recycling is currently considered an important means of packaging waste management. Assessing the safety of recycled packaging is very important because recycling can increase the levels of potentially hazardous chemicals in packaging and in the food after they are migrated. Various food packaging materials such as plastic, paper and cardboard, aluminum, steel, and multi-material multi-layers packaging are commonly used, but only the recycling safety of plastic food packaging materials, which is the most used and has a significant increase in post-use problem, is discussed in this review.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.4
• /
• pp.123-136
• /
• 2021

Teddy bear is a typical rag doll which has been loved by people all over the world for more than 100 years based on its cute and friendly image. In addition, as it has been together for a long time with us, it is considered as a friend of people with memories of all ages and sexes, not just animal doll. Teddy bear has been developing its appearance and character continually playing a role as the symbol of society and issues of an era beyond toys, however it still remains in the image of stuffed toys. Therefore, more advanced teddy bear characters should be created in line with the current environment and market conditions that are undergoing major changes based on the Internet and smart phones. Thus, the concept of the character and the recent development of the market were reflected and the meaning and current image of teddy bears were analyzed to develop new teddy bear stories, worldviews, and characters through design process. And it was created 3D characters, videos, and SNS channels through the developed 3D character design and motion design. Furthermore, we want to take a look at the direction in which Korea's character business can develop in accordance with global changes and suggest the possibility of entering as a character powerhouse.

• Membrane Journal
• /
• v.32 no.5
• /
• pp.283-291
• /
• 2022

Hydrogen energy has received much attention as a solution to the supply of renewable energy and to respond to climate change. Hydrogen is the most suitable candidate of storing unused electric power in a large-capacity long cycle. Among the technologies for producing hydrogen, water electrolysis is known as an eco-friendly hydrogen production technology that produces hydrogen without carbon dioxide generation by water splitting reaction. Membranes in water electrolysis system physically separate the anode and the cathode, but also prevent mixing of generated hydrogen and oxygen gases and facilitate ion transfer to complete circuit. In particular, the key to next-generation anion exchange membrane that can compensate for the shortcomings of conventional water electrolysis technologies is to develop high performance anion exchange membrane. Many studies are conducted to have high ion conductivity and excellent durability in an alkaline environment simultaneously, and various materials are being searched. In this review, we will discuss the research trends and points to move forward by looking at the research on anion exchange membranes based on commercial polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) block copolymers.

• Clean Technology
• /
• v.16 no.2
• /
• pp.88-94
• /
• 2010

The physiological roles of various wavelength of light emitting diode (LED) on ‘Hayward’ kiwifruit experiencing after-ripening were investigated. Various wavelengths from LED light source were irradiated on kiwifruits kept in plastic bags or under open air at $25^{\circ}C$. During two weeks of storage, firmness of Hayward kiwifruits was decreased by $25^{\circ}C$ treatment than by $4^{\circ}C$ treatment. In the $25^{\circ}C$ storage condition, the firmness of kiwifruits was decreased by the treatment of 380 nm UV and 470nm white LED light source. Sweetness of kiwifruits treated with 380 nm UV LED and dark condition at $25^{\circ}C$ increased higher than $15^{\circ}$Brix. The acidity of kiwifruits under open air was decreased 52% by incubating at $25^{\circ}C$ with 660 nm red LED treatment. The acidity of kiwifruits in plastic bags was decreased 52.6, 55.6, 52.8% by the treatment of 440 nm blue, 470 nm white and 660 nm red LED light source, respectively, compared to that of kiwifruits incubated in darkness at $25^{\circ}C$. Decreased acidity irradiated by 660 nm red LED light source can be applied for regulating periods of the kiwifruit after-ripening process. LED light sources emit very narrow wavelength with a power-saving mode, therefore, the usage of these LED light source for regulating the after-ripening process can be classified as a clean biotechnology producing safe and environment-friendly kiwifruits.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.2
• /
• pp.273-278
• /
• 2024

The purpose of this study is to examine the limitations of university operating system changes as a result of the policy changes and outcomes of the university lifelong education system support project by project period, and based on this, to propose a development plan to support the university's adult learning system. In this study, we sought to investigate changes in the higher education environment and changes in lifelong education in universities through analysis of literature and various data. The changing times of technological innovation and changes in knowledge require continuous learning even after school education, and the need for re-education and improved education is increasing. Therefore, the Ministry of Education and the National Institute for Lifelong Education have been actively carrying out support projects for lifelong learning-centered universities since 2008 to provide adult learners with opportunities to study. This project is centered around universities and the local community, and is promoting various types of changes in educational operation, such as reforming the university's academic system to be adult-friendly and operating night or weekend classes in order to provide educational opportunities for adult learners. Now, universities must play a role as a hub of regional lifelong education for the coexistence of the region and university, and as a key institution responsible for the contemporary tasks of sustainable development and coexistence between the university and the community.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.1
• /
• pp.379-386
• /
• 2024

The purpose of this study was to pay attention to the increase in the frequency of expression of butterflies and insects, whose decrease in the number of individuals is symbolized as a measure of environmental pollution, among the various motifs of nature as we go through the COVID-19, when we realized the importance of nature. The scope of this study was limited to fashion collection fashion show photos and interview articles of online for fashion collections from 2019 to 2023. As a result of the study, 185 butterfly motivation fashion design appeared, and digital printing techniques were the most used as a type of plane expression method. Along with this, techniques such as quilting, embroidery, and beading have appeared a lot as techniques to express the planar motif of butterflies. As for the three-dimensional expression types, 3D printing, laser cutting, corsage techniques, and draping techniques showed similar proportion. It can be seen that the expressed butterfly motif had more realistic description the shape of the butterfly as it was than abstract expressions. In conclusion, it can be seen that the butterfly motif fashion design over the past five years contains a stronger message about the environment than the butterfly motif fashion in the past. It was confirmed that it is a motif with a great symbolic meaning that can convey an eco-friendly message beyond just the morphological beauty and colorful design elements of the butterfly.