• Korean Journal of Materials Research
• /
• v.10 no.4
• /
• pp.290-294
• /
• 2000

ZnS:Mn TFEL devices were fabricated by electron-beam evaporation method and then the electro-optical properties were investigated. To investigate the capacitance which was due to oxygen vacancy at the $Ta_2O_5$ thin film, AES(Auger Electron Spectroscopy) and C-F(capacitance-frequency) measurements were used. It was found that the capacitance was decreased by annealing the $Ta_2O_5$ film in oxygen ambience. From EL emission measurement, we observed the EL emission spectrum which had the peak range from 550nm and 650nm. This emission is associated with the transition from $^4T_1(^4G)$ first excited state to $^6A_1(^6S)$ ground state in the $3d^5$ energy level configuration of $Mn^{2+}$ occurs. The threshold voltage of EL device with $Ta_2O_5$ insulator layer was found to be 24V~28V. The CIE color coordinates of these emission are X=0.5151, Y=0.4202 which is yellowish orange emitting. The EL device using $Ta_2O_5$ insulator layer can be driven with a low voltage which is beneficial to the practical application.

• Journal of Environmental Science International
• /
• v.3 no.2
• /
• pp.165-175
• /
• 1994

An emergy analysis of the main energy flows driving the economy of humans and life support systems was made including environmental energies, fuels, and imports, all expressed as solar emjoules. The total emergy use (4, 373 E20 sej/yr) is 90 per cent from imported sources, fuels and goods and services. The emergy flows from the environment are modest, because the share of global inputs such as ruin and geological uplift flux is modest. Consequently, the ratio of outside investment to attracting natural resources is already large, like other industrialized countries. The population level is already in excess of carrying capacity. The emergy use per person in Korea indicates a moderate emergy standard of living, even though the indigenous resource is very poor. If the present economy were running entirely on stored reserves of fuels, soils, woods, etc., it would last about 2 years. Its carrying capacity for steady state on its renewable sources is only 3.3 million people, compared to 43.3 million in 1991. Continued availability of foreign oil at a favorable balance of emergy trade, currently about 7 to 1 net emergy, is the basis for present economic activity and must decrease as the net emergy of foreign oil purchased goes down. Close economic integration with Middle East may determine how long this is possible in the future.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.3
• /
• pp.491-499
• /
• 2019

Recently, there has been increasing demand for power quality in power supply devices. The IEC 61000-3-2 standard requires that the AC / DC power supply for lighting meet the specifications for the power factor (PF) and total waveform distortion (THD). In addition, advanced countries in Europe are regulating the ripple rate as 15 ~ 30% for the flicker phenomenon caused by the change in the amount of foot energy due to the change in current of the output terminal. Therefore, domestic standards and regulations are being updated. This study adopted the Flyback converter to satisfy the PFC standard, and has the circuit first and second insulation function. To reduce the low frequency ripple of the LED current, Flyback, Coupled Inductor, LC parallel resonance filter, LLC resonance filter, and Cuk were simulated by PSIM to mimic each LED driving circuit. A coupled LC resonant circuit with a coupled inductor on the primary side and LC resonance on the secondary side was also proposed for output side ripple reduction.

• The Journal of Korean Philosophical History
• /
• no.59
• /
• pp.395-423
• /
• 2018

Since the middle of the 19th century, East Asia, especially Korea, was oppressed externally by the imperialism of Japan and others while internally long-lasting political convention like in-law government was driving the country into troubles at home and abroad. Witnessing such a situation and building up scholarly capability through reading over nearly all spheres, a Confucian philosopher, Ch'oe Han-gi (崔漢綺, 1803-1877), philosophized about the clue to the solution of such a choking phenomenon. Ch'oe believed that there was movement, ki (matter, material force, energy) of revolving transformation inherent in all things, people, or objects. Grasping even the principle and order of existence inherent in things from the viewpoint of ki, he tried to change the traditional theory on the law of existence of things that there existed an ontological reason lacking in motility, which was more dominant than anything existing in the universe and which ruled over the world. From this, he elucidated that the Way, an identity that rules over all affairs and things, was not simply one but diverse. This means, on one hand, that he tentatively accepted the relativity of things. On the other hand, he also taught us "oneness in all things" in which all including human beings exist in close connection to each other transcending the relativity or "agreement" in which they exist in harmony as one and "unity" in which they are united into one.

• The Journal of Korean Philosophical History
• /
• no.41
• /
• pp.9-38
• /
• 2014

Hanhweon-dang Kim Goeng-pil(1454~1504) sublimated ethics whose lead was opened up by Jeong Mong-ju in late Goryeo as one scholarly tendency. Kim Goeng-pil was called 'the father of ethics in Joseon' and has been respected as a model of ethicist for 400 years since then. Following Kim Goeng-pil, Confucian scholars of Joseon cultivated perseverance through Xiaoxue and the perseverance was sublimated to Confucian scholars' energy and then that of state, which served as driving force to keep the national legacy. Kim Goeng-pil suggested how to study with Xiaoxue and sought moral human beings and ethically ideal societies based on strong practicability which is required in Xiaoxue. Individuals' cultivation and social reform are not at a different dimension. Spirit of 'self-cultivation' that Kim Goeng-pil himself demonstrated advanced to pursuit of ethical, ideal state when reaching a level of Jo Kwang-jo. Kim Goeng-pil thought that teaching in Xiaoxue could be achieved through 'Gyeong (敬, respect).' It is the key of Neo-Confucianism in Joseon to control one's mind through the cultivating method of 'Gyeong.' Kim Goeng-pil settled Joseon's Confucianism as 'practical ethics(心學).' Before Kim Goeng-pil, no scholars had well presented the aspects of practical ethics. After King Myeongjong and Seonjo, Confucianism in Joseon worked as the cornerstone of practical ethics. Since mid-17th century, the system of practical ethics had been firmly established with focus on 'Gyeong. Literary men of Kim Goeng-pil and scholars they fostered led the academic and political world of Joseon after mid-16th century. They played the lead in Sarim faction's(士林派) ruling after King Seonjo came to throne. The very foundation which sublimated Joseon to the ethically ideal state and made the Dynasty a 'state of Sarim' was actually laid by Kim Goeng-pil.

• The Journal of the Korea Contents Association
• /
• v.21 no.5
• /
• pp.70-83
• /
• 2021

The issue of predicting the relationship between humans and AI robots is a 'strong AI' problem. Many experts predict the tragic ending which is a strong AI with superior thinking ability than humans will conquer humans. Due to the expectations of AI robots are projected onto media, the 'morally good AI' that meets human expectations is an important issue. However, the demand for good AI and the realization of perfect technology is not limited to machines. Rather, it appears as a result of putting all responsibility on humans, driving humans into immoral beings and turning them into human and human problems, which is resulting in more alienation and discrimination. As such, the result of technology interacts with the human being used and its properties are determined and developed according to the reaction. This again affects humans. Therefore, AI technology that considers human emotions in consideration of interaction is also important. Therefore, this study will clarify the process that the demand for 'Good AI' in the relationship of AI to humans with Randall Collins' Interaction Ritual Chain. Emotional energy in Interaction Ritual Chain has explained the formation of human bonds. Also, the methodology is a type of thinking experiment and explained through Janet and surrounding characters in the TV show .

• Applied Chemistry for Engineering
• /
• v.33 no.1
• /
• pp.50-57
• /
• 2022

Ti-In-Zn-O (TIZO)/Ag/TIZO multilayer transparent electrodes were prepared on glass substrates at room temperature using RF/DC magnetron sputtering. Obtained multilayer structure comprising TIZO/Ag/TIZO (10 nm/10 nm/40 nm) with the total thickness of 60 nm showed a transmittance of 86.5% at 650 nm and a sheet resistance of 8.1 Ω/□. The multilayer films were expected to be applicable for use in energy-saving smart window based on polymer-dispersed liquid crystal (PDLC) because of their transmittance properties to effectively block infrared rays (heat rays). We investigated the effects of the content ratio of prepolymer, the thickness of the PDLC coating layer, and the ultraviolet (UV) light intensity on electro-optical properties, and the surface morphology of polyester acrylate-based PDLC systems using new TIZO/Ag/TIZO transparent conducting electrodes. A PDLC cell with a thickness of 15 ㎛ PDLC layer photocured at an UV intensity of 1.5 mW/cm² exhibited good driving voltage, favorable on-state transmittance, and excellent off-haze. The LC droplets formed on the surface of the polymer matrix of the PDLC composite had a size range of 1 to 3 ㎛ capable of efficiently scattering incident light. Also, the PDLC-based smart window manufactured using TIZO/Ag/TIZO multi-layered transparent electrodes in this study exhibited a light brown, which will have an advantage in terms of aesthetics.

• Journal of Convergence for Information Technology
• /
• v.11 no.4
• /
• pp.83-101
• /
• 2021

This study is to investigate, using AHP, what technologies should be applied first to Korean SMEs in order to respond to the 4th industrial revolution and change to a smart enterprise. To this end, technologies related to the 4th industrial revolution and smart factory are synthesized, and the classification criteria of Dae-Hoon Kim et al. (2019) are applied, but additional opinions of experts are collected and related technologies are converted to artificial intelligence (AI), Big Data, and Cloud Computing. As a base technology, mobile, Internet of Things (IoT), block chain as hyper-connected technology, unmanned transportation (autonomous driving), robot, 3D printing, drone as a convergence technology, smart manufacturing and logistics, smart healthcare, smart transportation and smart finance were classified as smart industrial technologies. As a result of confirming the priorities for technical use by AHP analysis and calculating the total weight, manufacturing companies have a high ranking in mobile, artificial intelligence (AI), big data, and robots, while service companies are in big data and robots, artificial intelligence (AI), and smart healthcare are ranked high, and in all companies, it is in the order of big data, artificial intelligence (AI), robot, and mobile. Through this study, it was clearly identified which technologies should be applied first in order to respond to the 4th industrial revolution and change to a smart company.

• Korean Chemical Engineering Research
• /
• v.61 no.3
• /
• pp.362-367
• /
• 2023

Recently, research and development of proton exchange membrane fuel cells (PEMFC) membranes are progressing in the direction of thinning to reduce prices and improve performance. Demand for hydrogen-powered vehicles for commercial vehicles is also increasing, and their durability should be five times greater than those for passenger vehicles. Despite the thinning of the membranes, the durability of the membranes must be increased five times, so the improvement of the durability of the membranes has become more important. Since the acceleration durability evaluation time also needs to be shortened, the protocol using oxygen instead of air in the existing protocol was applied to a 10 ㎛ thin membrane to evaluate durability. The accelerated durability test (Open circuit voltage holding) was terminated at 720 hours. If the air-based department of energy (DOE) protocol was used, a lifespan of 450,000 km of driving hours would be expected, with a durability of about 1,500 hours. During the chemical durability evaluation, the active area of the electrode decreased by 51%, suggesting that catalyst degradation had an effect on membrane durability. Reducing the catalyst degradation rate is expected to increase membrane durability.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.1
• /
• pp.305-316
• /
• 2013

To find out if modern roundabout is still effective under drivers behavior and driving conditions in Busan Metropolitan City, the effects before and after introduction of roundabout were analyzed. According to analysis on velocity profile at roundabout, velocity deviation decreased, and average vehicle speed was close to design speed. As a result, it has been confirmed that most roundabouts were properly built. In terms of traffic operation, average vehicle speed improved by 87.2% when a traffic intersection was replaced by a roundabout. therefore, it has been found out that the introduction of roundabout has a positive effect on increasing vehicle speed by reducing traffic congestion. In addition, annual benefits expected from the replacement from a traffic intersection to a roundabout were KRW 872 million as follows; KRW 410 million in traffic communication, KRW 39 million in transportation safety, KRW 255 million in energy saving, KRW 95 million in reduction of air pollution and KRW 73 million in reduction of traffic signal installation cost. In other words, if 10% (193 spots) of all traffic intersections (1,926 spots in total) in Busan City are replaced by roundabouts, the municipal authority would be able to save about KRW 168.3 billion. According to analysis on the benefits expected from the installation of roundabouts compared to the investment cost for traffic intersections, about KRW 679 million could be saved per roundabout. Considering 10% of all traffic intersections in the City of Busan, about KRW 131 billion could be saved annually. The traffic accidents in roundabout usually occur because drivers aren't aware of right-of-way rules. Once the right-of-way rules settle, the number of traffic accidents would significantly decrease. In addition, it is urgent to promote education and campaign for drivers, pedestrians and bikers on the roundabout.